Dines Bjørner Cliff B. Jones Mícheál Mac an Airchinnigh Erich J. Neuhold VDM '87, VDM - A Formal Method at Work, VDM-Europe Symposium, Brussels, Belgium, March 23-26, 1987, Proceedings VDM Europe Lecture Notes in Computer Science 252 Springer 1987 3-540-17654-3 db/conf/fm/vdme1987.html