5-State Rotation-Symmetric Number-Conserving Cellular Automata are not Strongly Universal. - Katsunobu Imai; Hisamichi Ishizaka; Victor Poupet (Automata, 2014)

On Enumeration of Motion Representable Two-Dimensional Two-State Number-Conserving Cellular Automata. - Hisamichi Ishizaka; Yohei Takemura; Katsunobu Imai (CANDAR, 2015)

The Weak Universality of Two-Dimensional Five-State von Neumann Neighborhood Number-Conserving Cellular Automaton. - Hisamichi Ishizaka; GilTak Kong; Katsunobu Imai (New Gener. Comput., 2022)