Hartmut Ehrig Gregor Engels Hans-Jörg Kreowski Grzegorz Rozenberg Theory and Application of Graph Transformations, 6th International Workshop, TAGT'98, Paderborn, Germany, November 16-20, 1998, Selected Papers TAGT Lecture Notes in Computer Science 1764 Springer 2000 3-540-67203-6 db/conf/tagt/tagt1998.html