Herbert Göttler Hans Jürgen Schneider Graph-Theoretic Concepts in Computer Science, International Workshop, WG '87, Kloster Banz/Staffelstein, Germany, June 29 - July 1, 1987, Proceedings WG Lecture Notes in Computer Science 314 Springer 1988 3-540-19422-3 db/conf/wg/wg87.html