¹This presentation is from Combinatorial Algorithms by T. C. Hu, Addison-Wesley, 1982
[2]Data Structures and Algorithms 1: Sorting and Searching by Kurt Melhorn 1984, p 180
[3]Data Structures and Algorithms 1: Sorting and Searching by Kurt Melhorn 1984, p 181
[4]Data Structures and Algorithms 1: Sorting and Searching by Kurt Melhorn 1984, p 182
[5]E.S. Schwartz, JACM 10 (1963), 413 - 439
⁶Constructing Nearly Optimal Lexicographical Trees by Walker and Gotieb in Graph Theorey and Computing Ed Ronald Read, 1972 pp303-323