* [https://www.ivifoundation.org/downloads/SCPI/scpi-99.pdf SCPI-1999, Volume 1-4], 819 page PDF file, '''free''' in 2024 ''(doesn't include asterisk (*) commands, because they are specified in IEEE 488.2)''
* [https://wwwieeexplore.techstreetieee.comorg/ieeedocument/standards/ieee-488-2-1992?product_id=18886348705775 IEEE 488.2-1992], 254 page PDF file, costs [https://www.techstreet.com/ieee/standards/ieee-488-2-1992?product_id=1888634 USD$52] in 2024 ''(replaces [https://www.techstreet.com/ieee/standards/ieee-488-2-1987?product_id=1777534 IEEE 488.2-1987], both superseded by IEEE/IEC 60488-2-2004)''