Describing and Verifying Programs with Abstract Data Types. - Reiji Nakajima; Michio Honda; Hayao Nakahara (Formal Description of Programming Concepts, 1977)

Hierarchical Program Specification and Verification - a Many-sorted Logical Approach. - Reiji Nakajima; Michio Honda; Hayao Nakahara (Acta Informatica, 1980)