Beyond Prolog: Software Specification by Grammar. - Walter W. Wilson (ACM SIGPLAN Notices, 1982)

A minimal specification language. - Walter W. Wilson (LOPSTR, 2000)

Implementation of Axiomatic Language. - Walter W. Wilson (ICLP (Technical Communications), 2011)

A Tiny Specification Metalanguage. - Walter W. Wilson; Yu Lei (SEKE, 2012)