One Step Transformation of Periodic Sequences by Cellular Automata. - Hisao Yamada; Masatosi Imori (SIAM J. Comput., 1983)

Periodic Character Sequences where Identifying two Characters Strictly Reduces the Period. - Masatosi Imori; Hisao Yamada (Theor. Comput. Sci., 1985)

The line digraph of a regular and pancircular digraph is also regular and pancircular. - Masatosi Imori; Makoto Matsumoto; Hisao Yamada (Graphs Comb., 1988)