. Warfield included this paper as part of his 1986 GRAILS proposal, as an appendix. Techniques are introduced which are applicable to machine construction of digraph maps.
A team of Japanese researchers K. Sugiyama, S. Tagawa and M. Toda, at Fujitsu, Ltd. In Tokyo, developed and published in 1981 a superior algorithm for structuring, based on the work Warfield did in "Crossing Theory & Hierarchical Mapping". It is titled: "Effective Representations of Hierarchical Structures, Research Report No.8." See a Japanese paper "Methods for Visual Understanding of Hierarchical System Structures” and see also the Fujitsu Research Report on which the Japanese journal article is based.
Warfield discusses the Japanese researcher's work at length in his 1990 book, "A Science of Generic Design" and gives Sugiyama, Tagawa & Toda full credit and a full bibliography reference for their improvement on his 1977 algorithm.
See also IASIS File 77/004, for a software package based on Warfield's paper, written by R. R. Cline, who was a student at University of Virginia in 1977.