* Chapter[[Thomas 21H. Cormen]], [[Charles E. Leiserson]], [[Ronald L. Rivest]], and [[Clifford Stein]]. ''[[Introduction to Algorithms]]'', 2ndSecond edEdition. Cormen,MIT Leiserson,Press Rivestand McGraw-Hill, Stein1990. ISBN 0262032937. Chapter 21: Data structures for Disjoint Sets, pp.498–524.