On the Integration of Roles in the UML
R. Depke, G. Engels, J. Küster, On the Integration of Roles in the UML, University of Paderborn, Department of Computer Science, 2000.

Modeling Agent-Based Systems with Graph Transformation
R. Depke, R. Heckel, J. Küster, Modeling Agent-Based Systems with Graph Transformation, University of Paderborn, Department of Computer Science, 2000.

UML Collaboration Diagrams and Their Transformation to Java
G. Engels, R. Hücking, S. Sauer, A. Wagner, UML Collaboration Diagrams and Their Transformation to Java, University of Paderborn, Department of Computer Science, 1999.

Graph Transformation for Specification and Programming
M. Andries, G. Engels, A. Habel, B. Hoffmann, H.-J. Kreowski, S. Kuske, D. Plump, A. Schürr, G. Taentzer, Graph Transformation for Specification and Programming, University of Bremen, Department of Mathematics and Computer Science, 1996.

Operational Semantics of Algebraic Specifications with Conditional Equations
U. Pletat, G. Engels, H.-D. Ehrich, Operational Semantics of Algebraic Specifications with Conditional Equations, University of Dortmund, Department of Computer Science, 1981.