1. A Note on the Snake-in-the-Box Problem, unpublished manuscript. Some Problems in Combinatorial Analysis;Abbott,1965
2. Electronic Combination Lock;Black,1964
3. Longest “Separated” Paths and Loops in an N Cube;Davies;IEEE Trans. Electronic Computers,1965
4. Snake-in-the-Box Codes;Even;IEEE Trans. Electronic Computers,1963
5. Gray Codes and Paths on the n-Cube;Gilbert;Bell System Tech. J.,1958