Exor Decomposition with Common Variables and its Application to Multiple-Output Networks. - Ryoji Ishikawa; Goro Koda; Kensuke Shimizu; Takashi Hirayama (J. Circuits Syst. Comput., 1999)

Pseudocube-based expressions to enhance testability. - Ryoji Ishikawa; Tomonori Igarashi; Takashi Hirayama; Kensuke Shimizu (APCCAS (2), 2002)

New Three-Level Boolean Expression Based on EXOR Gates. - Ryoji Ishikawa; Takashi Hirayama; Goro Koda; Kensuke Shimizu (IEICE Trans. Inf. Syst., 2004)