Dirk Janssens, Grzegorz Rozenberg. Generating Graph Languages Using Hypergraph Grammars. In Ferenc Gécseg, editor, Fundamentals of Computation Theory, FCT 81, Proceedings of the 1981 International FCT-Conference, Szeged, Hungary, August 24-28, 1981. Volume 117 of Lecture Notes in Computer Science, pages 154-164, Springer, 1981.