Gio Wiederhold and John Ehrman, "Inferred SYNTAX and SEMANTICS of PL/S", Proceedings of the SIGPLAN symposium on Languages for system implementation 1971, in SIGPLAN Notices 6(10) October 1971 Guide to PL/S II, International Business Machines Corp., 1974.
Gio Wiederhold, John Ehrman: Inferred SYNTAX and SEMANTICS of PL/S. In: Proceedings of the SIGPLAN symposium on Languages for system implementation 1971, SIGPLAN Notices Band 6, (10), Oktober 1971 Guide to PL/S II, International Business Machines Corp., 1974.