Manhattan Project feed materials program: Difference between revisions

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{{main|Manhattan Project}}

[[File:Uranium processing.png|thumb|right|upright=1.3|Chart describing the processing of uranium]]

The '''Manhattan Project feed materials program''' located and procured [[uranium ore]]s, and refined and processed them into feed materials for use in the [[Manhattan Project]]'s [[isotope enrichment]] plants at the [[Clinton Engineer Works]] in [[Oak Ridge, Tennessee]], and its [[nuclear reactor]]s at the [[Hanford Engineer Works]] in [[Washington state]]. The [[highly enriched uranium]] product of the enrichment plants and the [[plutonium]] from the reactors was used to make [[atomic bomb]]s.

The original goal of the feed materials program in 1942 was to acquire approximately {{convert|1,700|ST|t|order=flip}} of [[triuranium octoxide]] ({{chem2|U3O8}}) (black oxide). By the time of the dissolution of the Manhattan District on 1 January 1947, it had acquired about {{convert|10,000|ST|order=flip}}, {{Percentage|6983|10220|1}} of which came from the [[Belgian Congo]], {{Percentage|1349|10220|1}} from the [[Colorado Plateau]], and {{Percentage|1137|10220|1}} from Canada. An additional {{Percentage|481+270|10220|1}} came from "miscellaneous sources", which included quantities recovered from Europe by the Manhattan Project's [[Alsos Mission]].

Ores from the Belgian Congo contained the most uranium per mass of rock by far. Much of the mined ore from the [[Shinkolobwe]] mine had a black oxide content as high as 65% to 75%, which was many times higher than any other global sources. In comparison, the Canadian ores could be as rich as 30% uranium oxides, while American ores, mostly byproducts of the mining of other minerals (especially [[vanadium]]), typically contained less than 1% uranium. In 1941, both the Shinkolobwe mine and the [[Eldorado Mine (Northwest Territories)|Eldorado Mine]] in Canada were closed and became flooded; the Manhattan Project had them reopened and returned to service.

Beyond their immediate wartime needs, the American and British governments attempted to control as much of the world's uranium deposits as possible. They created the [[Combined Development Trust]] in June 1944, with the director of the Manhattan Project, [[Major General (United States)|Major General]] [[Leslie R. Groves Jr.]] as its chairman. The Combined Development Trust procured uranium and [[thorium#Occurrence|thorium ores]] on international markets. A special account not subject to the usual auditing and controls was used to hold Trust monies. Between 1944 and his resignation from the Trust in 1947, Groves deposited a total of $37.5 million (equivalent to ${{Inflation|US|37.5|1944|r=2}} million in {{Inflation/year|US}}). In 1944, the Combined Development Trust purchased {{convert|3440000|lb|kg}} of uranium oxide ore from the Belgian Congo.

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In August 1943, [[Winston Churchill]] and [[Franklin Roosevelt]] negotiated the [[Quebec Agreement]], which merged the British and American atomic bomb projects,{{sfn|Gowing|1964|pp=168–173}}{{sfn|Bernstein|1976|pp=216–217}} and established the [[Combined Policy Committee]] to coordinate their efforts.{{sfn|Jones|1985|p=296}} In turn, the Combined Policy Committee created the [[Combined Development Trust]] on 13 June 1944 to procure uranium and [[thorium#Occurrence|thorium ores]] on international markets.{{sfn|Helmreich|1986|p=16}} Groves was appointed its chairman, with Sir [[Charles Jocelyn Hambro|Charles Hambro]], the head of the British Raw Materials Mission in Washington, [[Frank Godbould Lee|Frank Lee]] from the [[HM Treasury|Treasury]] delegation as the British trustees, and George Bateman, a deputy minister and a member of the [[Combined Production and Resources Board]], representing Canada.{{sfn|Gowing|1964|p=301}}{{sfn|Jones|1985|p=299}} A special account not subject to the usual auditing and controls was used to hold Trust monies. Between 1944 and his resignation from the Trust at the end of 1947, Groves deposited a total of $37.5 million (equivalent to ${{Inflation|US|37.5|1944|r=2}} million in {{Inflation/year|US}}).{{sfn|Jones|1985|pp=90, 299–306}}

In the autumn of 1943, Groves triedattempted to have the Shinkolobwe mine re-opened and its output sold to the United States.{{sfn|Hewlett|Anderson|1962|pp=285–286}} Sengier reported that the mine could yield another {{convert|10,000|ST|t|order=flip}} of ore containing 50 to 60 per cent oxide, but restarting production required new equipment, electricity to pump out the flooded mine, and assembling a workforce, which would take 18 to 20 months.{{sfn|Helmreich|1986|p=18}} Mine repairs and dewatering cost about $350,000 and another $200,000 was required to divert electricity away from copper mines.{{sfn|Helmreich|1986|p=35}} As 30 per cent of the stock in Union Minière were held by British shareholders and the [[Belgian Government in Exile]] was in London, the British took the lead in negotiations.{{sfn|Hewlett|Anderson|1962|pp=285–286}} Negotiations took much longer than anticipated, but Sir [[John Anderson, 1st Viscount Waverley|John Anderson]] and Ambassador [[John Winant]] hammered out a deal in May 1944 with Sengier and the Belgian Government in Exile for the mine to be reopened and {{convert|1720|ST}} of ore to be purchased, and the contract was signed until 25 September 1944.{{sfn|Helmreich|1986|pp=36–37}} The agreement between the United States, the United Kingdom, and Belgium lasted ten years and financed the development of [[nuclear energy in Belgium]].{{sfn|Helmreich|1990|pp=320-321}}

====Post-war====

Groves tried to have the Shinkolobwe mine re-opened and its output sold to the United States.{{sfn|Hewlett|Anderson|1962|pp=285–286}} Sengier reported that the mine could yield another {{convert|10,000|ST|t|order=flip}} of ore containing 50 to 60 per cent oxide, but restarting production required new equipment, electricity to pump out the flooded mine, and assembling a workforce, which would take 18 to 20 months.{{sfn|Helmreich|1986|p=18}} Mine repairs and dewatering cost about $350,000 and another $200,000 was required to divert electricity away from copper mines.{{sfn|Helmreich|1986|p=35}} As 30 per cent of the stock in Union Minière were held by British shareholders and the [[Belgian Government in Exile]] was in London, the British took the lead in negotiations.{{sfn|Hewlett|Anderson|1962|pp=285–286}} Negotiations took much longer than anticipated, but Sir [[John Anderson, 1st Viscount Waverley|John Anderson]] and Ambassador [[John Winant]] hammered out a deal in May 1944 with Sengier and the Belgian Government in Exile for the mine to be reopened and {{convert|1720|ST}} of ore to be purchased, and the contract was signed until 25 September 1944.{{sfn|Helmreich|1986|pp=36–37}} The agreement between the United States, the United Kingdom, and Belgium lasted ten years and financed the development of [[nuclear energy in Belgium]].{{sfn|Helmreich|1990|pp=320-321}}

[[File:BOILER and PROCESS BUILDINGS, SOUTHWEST OBLIQUE - Middlesex Sampling Plant, Process Building, 239 Mountain Avenue, Middlesex, Middlesex County, NJ HAER NJ,12-MIDSX,1A-6.tif|thumb|left|Boiler and process buildings, [[Middlesex Sampling Plant]]]]

During the war, all uranium from the Congo had gone to the United States, as had that captured in Europe by the [[Alsos Mission]], although some of it passingpassed through British hands.{{sfn|Gowing|Arnold|1974|pp=102–103}} The entire output of Shinkolobwe was contracted to the Combined Development Trust until 1956, but in March 1946 there were (unrealized) fears that the mine might be exhausted in 1947, resulting in a severe uranium shortage.{{sfn|Gowing|Arnold|1974|pp=358–359}} After some negotiation, Groves and [[James Chadwick]], the head of the [[British Mission to the Manhattan Project]], agreed on a division of uranium ore production, with everything up to March 1946 going to the United States, and supplies being shared equally thereafter.{{sfn|Gowing|Arnold|1974|pp=102–103}}{{sfn|Gowing|Arnold|1974|pp=358–359}} Between [[VJ-Day]] and 31 March 1946, ore containing {{convert|850|ST|t|order=flip}} of oxide at a cost of USD$2,582,260 ({{Inflation|US|2,582,260|1946|fmt=eq}}). Production then picked up as the effect of new machinery was felt, and from 1 April to 1 July {{convert|1,969|ST|t|order=flip}} of oxide was delivered at a cost of $7,113,956 ({{Inflation|US|7,113,956|1946|fmt=eq}}).{{sfn|Helmreich|1986|p=117}}

At the Combined Policy Committee meeting on 31 July 1946, the financial arrangements were adjusted. Previously, the two countries had split the costs equally; henceforth each would pay for only what they received.{{sfn|Gowing|Arnold|1974|pp=102–103}} Britain was therefore able to secure the uranium it needed for [[High Explosive Research]], its own nuclear weapons program, without having to outbid the United States, and paid for it in [[pound sterling|sterling]]. Meanwhile, because the adjustment applied retrospectively to VJ-Day, it received reimbursement for the supplies allocated to Britain but given to the United States, thus easing Britain's dollar shortage.{{sfn|Gowing|Arnold|1974|pp=102–103}}{{sfn|Gowing|Arnold|1974|p=356}} Although Union Minière would have preferred payment in dollars, it had to accept half in sterling.{{sfn|Helmreich|1986|p=117}}

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On 16 May, LaBine found pitchblende near the shores of Echo Bay at a mine site that became [[Port Radium]].{{sfn|Bothwell|1984|pp=23–25}}<ref>{{cite magazine |title=Science: Radium |magazine=[[Time (magazine)|Time]] |url=https://time.com/archive/6757353/science-radium/ |access-date=25 February 2025 }}</ref> Eldorado also established a processing plant at Port Hope, Ontario, the only facility of its kind in North America. To run it, LaBine hired Marcel Pochon, a French chemist who had learned how to refine radium under [[Pierre Curie]], who was working at the recently closed [[South Terras mine]] in Cornwall.{{sfn|Bothwell|1984|pp=55–57}}<ref>{{cite web |title=How Canada supplied uranium for the Manhattan Project |publisher=CBC Documentaries |url=https://www.cbc.ca/documentaries/how-canada-supplied-uranium-for-the-manhattan-project-1.7402051 |access-date=25 February 2025 |archive-date=11 February 2025 |archive-url=https://web.archive.org/web/20250211161617/https://www.cbc.ca/documentaries/how-canada-supplied-uranium-for-the-manhattan-project-1.7402051 |url-status=live }}</ref><ref>{{cite magazine |title=Science: Radium |magazine=[[Time (magazine)|Time]] |url=https://content.time.com/time/subscriber/article/0,33009,758086-2,00.html |access-date=25 February 2025 |url-access=subscription |archive-date=10 October 2023 |archive-url=https://web.archive.org/web/20231010121538/https://content.time.com/time/subscriber/article/0,33009,758086-2,00.html |url-status=live }}</ref> Ore was mined at Port Radium and shipped via [[Great Bear River|Great Bear]], [[Mackenzie River|Mackenzie]] and [[Slave River]]s to [[Waterways, Alberta]], and thence by rail to Port Hope.{{sfn|Bothwell|1984|pp=11–15}}<ref name="Macleans">{{cite magazine |title=Port Radium's Eldorado - The Mine that Shook the World |first=Ronald A. |last=Keith |magazine=Maclean's Magazine |date=15 November 1945 |via=Republic of Mining |url=https://republicofmining.com/2016/09/14/port-radiums-eldorado-the-mine-that-shook-the-world-by-ronald-a-keith-macleans-magazine-november-15-1945/ |access-date=26 February 2025}}</ref>

In 1936, Eldorado Gold Mines took over [[Marine Transportation Services|Northern Transportation Company Limited]] (NTCL). Its flagships were the ''[[Radium Queen (ship)|Radium Queen]]'' and ''[[Radium King]]'' both commissioned in 1937.{{sfn|Van Wyck|2010|p=31}}<ref>{{Cite news |date=15 April 1937 |title=Radium King's en route - Eldorado subsidiary ship leaves for west by train |url=https://news.google.com/newspapers?id=Gi8rAAAAIBAJ&sjid=qZgFAAAAIBAJ&pg=4583,2000389&dq=radium-king&hl=en |newspaper=The Montreal Gazette |volume=CLXVI |issue=90}}</ref> The two [[Tugboat|tugboats]] pulled or pushed, depending on the conditions, ore [[scow]]s named ''Radium One'' to ''Radium Twelve''.{{sfn|Bothwell|1984|pp=66–67}}<ref>{{cite news |title=Discouraging Difficulties Overcome by Eldorado Pioneers |newspaper=[[Edmonton Bulletin]] |date=11 December 1945 |page=16 |via=newspapers.com |url=https://www.newspapers.com/article/the-edmonton-bulletin/113391751/ |access-date=26 February 2025}}</ref> Great Bear Lake is only navigable between early July and early October, being icebound the rest of the year,{{sfn|Bothwell|1984|pp=11, 41}} but mining activity continued year-round, sustained by the [[Eldorado Radium Silver Express]], which flew personnel and supplies to the mine and transported ores back by air.{{sfn|Manhattan District|1947a|p=3.1}}{{sfn|Bothwell|1984|pp=368–375}}<ref name="CnsBulletin2005">{{cite journal |author=Arsenault |first=Jim E. |date=December 2005 |title=The Eldorado Radium Silver Express |url=https://cns-snc.ca/wp-content/uploads/2022/01/Vol26_No4_2005.pdf |journal=Canadian Nuclear Society Bulletin |issn= 0714-7074 |volume=26 |issue=4 |pages=47–49 |access-date=2012-12-0116 August 2025}}</ref>

Competition from Union Minière was fierce and served to drive the price of radium down from CAD$70 per milligram in 1930 ({{Inflation|CA|70|1930|fmt=eq}}) to CAD$21 per milligram in 1937 ({{Inflation|CA|21|1937|fmt=eq}}). Boris Pregel negotiated a cartel deal with Union Minière under which each company gained exclusive access to its home market and split the rest of the world 60:40 in Union Minière's favor. The outbreak of war in September 1939 blocked access to hard-won European markets, especially Germany, a major customer for ceramic-grade uranium. Union Minière lost its refinery at [[Olen, Belgium|Olen]] when Belgium was overrun, forcing it to use Eldorado's mill at Port Hope.{{sfn|Bothwell|1984|pp=71–75}} With sufficient stocks on hand for five years of operations, Eldorado closed the mine in June 1940.{{sfn|Manhattan District|1947a|p=3.1}}{{sfn|Bothwell|1984|pp=102–107}}

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On 15 June 1942, [[Malcolm MacDonald]], the [[List of high commissioners of the United Kingdom to Canada|United Kingdom high commissioner to Canada]], [[George Paget Thomson]] from the [[University of London]] and [[Michael Perrin]] from Tube Alloys met with [[Mackenzie King]], the [[Prime Minister of Canada]], and briefed him on the atomic bomb project. A subsequent meeting was arranged that same day at which the trio met with [[C. D. Howe]], the [[Department of Munitions and Supply|Minister for Munitions and Supply]] and [[Jack Mackenzie|C. J. Mackenzie]], the president of the [[National Research Council Canada]]. The British had noticed how uranium prices had been rising and feared that Pregel would attempt to corner the market, and they urged that Eldorado be brought under government control. Mackenzie proposed to effect this through secret purchase of the stock.{{sfn|Bothwell|1984|pp=119–121}} Howe then met with Gilbert LaBine, who agreed to sell his 1,000,303 shares at CDN$1.25 per share ({{Inflation|CA|1.25|1942|fmt=eq}}). This was a good deal for LaBine; the stock was trading at 40 cents a share at the time, but the stock only amounted to a quarter of the company's four million shares.{{sfn|Bothwell|1984|pp=123–124}}

Complex negotiations followed between the Americans, British and Canadians regarding patent rights, export controls, and the exchange of scientific information, but the purchase was approved when Churchill and Roosevelt met at the [[Second Washington Conference]] in June 1942.{{sfn|Hewlett|Anderson|1962|pp=85–86}} Over the next eighteen months, LaBine and John Proctor from the [[Imperial Bank of Canada]] criss-crossed North America buying up stock in EldoradoEl Dorado Gold Mines,{{sfn|Bothwell|1984|pp=123–124}} which changed its name to the more accurate Eldorado Mining and Refining on 3 June 1943.{{sfn|Manhattan District|1947a|p=3.1}} On 28 January 1944, Howe announced in the [[House of Commons of Canada]] that Eldorado had become a [[crown corporation]], and the remaining shareholders would be reimbursed at CSN$1.35 a share.{{sfn|Bothwell|1984|p=149}}<ref>{{cite web |first=Clarence Decatur |last=Howe |author-link=C. D. Howe |date=28 January 1944 |title=Acquisition of Properties and Assets by Expropriation of Capital Shares |publisher=Lipad - Linked Parliamentary Data Project |via=University of Toronto |url=https://www.lipad.ca/full/1944/01/28/2/ |access-date=16 August 2025}}</ref> Many shareholdeers had paid considerably more, but the government insisted that this was fair price,{{sfn|Sims|1980|p=39}} as the final market price was CDN$1.31 per share.{{sfn|Bothwell|1984|p=149}}

Shortly after the nationalization of Eldorado Gold Mines, the Canadian government initiated an investigation into the company's historical management practices and operations thathat yielded evidence suggesting fraudulent activities.<ref name=":0">{{Cite magazine |last=Sylvain |first=Lumbroso |last2=Wentzell |first2=Tyler |date=2 January 2024 |title=Unearthing a Nuclear Scandal |url=https://thewalrus.ca/unearthing-a-nuclear-scandal/ |access-date=26 April 2025 |magazine=[[The Walrus]] }}</ref> As a result, in February 1946, Marcel Pochon, financial director Carl French, and Boris Pregel were charged with criminal conspiracy and fraud. They were alleged to have misappropriated and significant funds from Eldorado through a network of secretly controlled companies.<ref>{{Cite news |date=12 February 1946 |title=Uranium To Forefront In Spy Ring Inquiry |url=https://princealbertlibrary.ca/padh/1946/February/Feb%2019,1946.pdf |newspaper=[[Prince Albert Daily Herald]] |pages=1, 8 |access-date=26 April 2025 }}</ref> However, the criminal proceedings against Pochon, French, and Pregel were discontinued. This decision was reportedly driven by the Canadian government's desire to avoid public disclosure of potentially sensitive wartime transactions. Terms of any settlement reached with Eldorado remained confidential.<ref name=":0" /> Related scrutiny also brought to light reports that Pregel, operating with U.S. government authorization, had facilitated the sale of {{convert|500|lb|kg|abbr=in|order=flip}} of uranium oxide to the Soviet Union during the war period. This transaction indicated that the distribution of Canadian uranium was not solely confined to the Manhattan Project.<ref>{{cite magazine |title=Mining: Uranium Unlimited? |magazine=[[Time (magazine)|Time]] |issue=11 |date=13 March 1950 |pp=83–84 |url=https://time.com/vault/issue/1950-03-13/page/87/ |access-date=26 April 2025}}</ref>

====Production====

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Nor was this the end of it: on 22 December, Preger's Canadian Radium and Uranium Corporation placed an order for another {{convert|500|ST|t|order=flip}}. This meant not only that the mine would be reopened, but that it would be fully occupied with American orders until the end of 1944.{{sfn|Bothwell|1984|p=110}} The British now became alarmed: they had allowed {{convert|20|ST|t|order=flip}} of oxide earmarked for them to be diverted to the Americans, whose need was more pressing, but were now faced with being shut out entirely, with no uranium for the [[Montreal Laboratory]]'s reactor. The issue was resolved by the Quebec Agreement in August 1943.{{sfn|Gowing|1964|pp=182–187}}{{sfn|Villa|1981|pp=142–145}}

Ed Bolger, who had been the mine superintendent from 1939 to 1940, led the effort to reactivate the mine in April 1942. He arrived by air with an advance party of 25 and supplies, flown in by [[Canadian Pacific Air Lines]]. Some ore had been abandoned on the docks when the mine was closed, and could be shipped immediately, but reactivation was complicated. The mine had filled with water that had to be pumped out, and the water had rotted the timbers. One [[raise (mining)|raise]] was filled with helium. In order to thaw out the rock, electric heaters were brought in and ventilation was reduced, but this exposed the miner workers to a build up of radon gas. Bolger sought out the richest deposits and worked them first; in one [[vein (geology)|vein]], the oxide content was as high as 5%, but monthly production consistently fell short of targets, falling from a high of {{convert|80,000|ST|t|order=flip}} in August 1943 to {{convert|18,454|ST|t|order=flip}} in December.{{sfn|Bothwell|1984|pp=102–107}}{{sfn|Hewlett|Anderson|1962|p=85}}

[[File:Radium Queen at the Fort Fitzgerald docks, July 1, 1937.jpg|thumb|left|The ''Radium Queen'' at the dock in July 1937]]

Each season, some {{convert|1,200|to|1,400|ST|t|order=flip}} of freight was delivered to Port Radium by water, along with {{convert|2,500|to|3,000|ST|t|order=flip}} of oil for the diesel generators from [[Norman Wells]] on the Mackenzie River. Shipping supplies by water from Waterways cost {{convert|0.05|$/lb|order=flip}} (equivalent to ${{Inflation|CA|{{convert|0.05|/lb|order=flip|disp=number}}|1943}}/kg in {{Inflation/year|CA}}), while air freight from [[Edmonton]] cost {{convert|0.70|$/lb|order=flip}} (equivalent to ${{Inflation|CA|{{convert|0.70|/lb|order=flip|disp=number}}|1943}}/kg in {{Inflation/year|CA}}).<ref name="Macleans"/> LaBine asked the Americans to expedite the delivery of two new [[Lockheed Model 18 Lodestar]] aircraft to Canadian Pacific.{{sfn|Bothwell|1984|pp=102–107}} United States and Canadian military aircraft were used to move ore from Port Radium to Waterways. In 1943, {{convert|300|ST|t|order=flip}} of ore was moved by air.{{sfn|Hewlett|Anderson|1962|p=291}} He was also able to get some personnel released from the Canadian armed forces. By 1944, Eldorado had a work force of 230.{{sfn|Bothwell|1984|pp=102–107}}

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=== Europe ===

{{main|Alsos Mission}}

The Alsos Mission was the Manhattan Project's [[scientific intelligence]] mission that operated in Europe. It was commanded by Lieutenant Colonel [[Boris Pash]], with [[Samuel Goudsmit]] as his scientific deputy. It moved with the advance of the Allied armies (and sometimes ahead of them).{{sfn|Groves|1962|pp=207–208}} In September 1944, after the liberation [[Antwerp]], the mission secured the corporate headquarters of Union Minière in [[Antwerp]] and seized its records.{{sfn|Groves|1962|pp=218–219}} They discovered that over {{convert|1,000|t|ST|order=flip}} tons of refined uranium had been sent to Germany, but about {{convert|150|ST|t|order=flip}} remained at Olen.{{sfn|Pash|1969|pp=82–86}} They then set out for Olen, where they located {{convert|68|ST|t|order=flip}}, but found another {{convert|80|ST|t|order=flip}} were missing, having been shipped to France in 1940 ahead of the German invasion of Belgium.{{sfn|Groves|1962|pp=219–220}} Groves had the recovered uranium shipped to England and ultimately to the United States.{{sfn|Jones|1985|p=287}}

[[File:Alsos mealtime.jpg|thumb|left|Personnel of the [[Alsos Mission]] in Germany. [[Boris Pash]] is in the center, wearing a helmet.]]

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* {{cite book |last=Scalia |first=Joseph M. |title=Germany's Last Mission to Japan: The Failed Voyage of U-234 |publisher=Naval Institute Press |year=2000 |isbn=1-55750-811-9 |oclc=42290880 |url=https://archive.org/details/germanyslastmiss0000scal }}

* {{cite journal |last1=Seaborg |first1=G. T. |author-link1=Glenn Seaborg |first2=J. W. |last2=Gofman |author-link2=John Gofman |first3=R. W. |last3=Stoughton |title=Nuclear Properties of U233: A New Fissionable Isotope of Uranium |journal=[[Physical Review]] |issn=0031-899X |volume=71 |page=378 |date=15 March 1947 |issue=6 |doi=10.1103/PhysRev.71.378.2 }}

* {{cite book |last=Sims |first=Gordon H.E. |title=A History of the Atomic Energy Control Board |publisher=Ministere of Supply and Services Canada |___location=Ottawa |date=July 1980 |isbn=0-660-10812-7 |url=https://inis.iaea.org/records/89cdh-6pb20/files/14762380.pdf |access-date=16 August 2025}}

* {{cite book |last=Smyth |first=Henry DeWolf |author-link=Henry DeWolf Smyth |title=Atomic Energy for Military Purposes: the Official Report on the Development of the Atomic Bomb under the Auspices of the United States Government, 1940–1945 |___location=Princeton, New Jersey |publisher=Princeton University Press |year=1945 |oclc=770285|title-link=Smyth Report}}

* {{cite book |last=Vanthemsche |first=Guy |title=Belgium and the Congo, 1885-1980 |date=2012 |publisher=Cambridge University Press |___location=Cambridge |isbn=978-0-521-19421-1 |oclc=801193141 }}