Depke, Ralph, Gregor Engels, and Jochen Küster. On the Integration of Roles in the UML. University of Paderborn, Department of Computer Science, 2000.
LibreCat: /record/8207

Depke, Ralph, Reiko Heckel, and Jochen Küster. Modeling Agent-Based Systems with Graph Transformation. University of Paderborn, Department of Computer Science, 2000.
LibreCat: /record/8208

Engels, Gregor, Roland Hücking, Stefan Sauer, and Annika Wagner. UML Collaboration Diagrams and Their Transformation to Java. University of Paderborn, Department of Computer Science, 1999.
LibreCat: /record/8204

Andries, Marc, Gregor Engels, Annegret Habel, Berthold Hoffmann, Hans-Jörg Kreowski, Sabine Kuske, Detlef Plump, Andy Schürr, and Gabriele Taentzer. Graph Transformation for Specification and Programming. University of Bremen, Department of Mathematics and Computer Science, 1996.
LibreCat: /record/8197

Pletat, Udo, Gregor Engels, and Hans-Dietrich Ehrich. Operational Semantics of Algebraic Specifications with Conditional Equations. University of Dortmund, Department of Computer Science, 1981.
LibreCat: /record/8185