1. Chaochen, Z., Hoare, C.A.R., Ravn, A.P.: A Calculus of Durations. Inform. Proc. Letters 40(5), 269–276 (1991)
2. Dierks, H., Tapken, J.: Tool-Supported Hierarchical Design of Distributed Real-Time Systems. In: Euromicro Workshop on Real Time Systems, pp. 222–229. IEEE, Los Alamitos (1998)
3. Lecture Notes in Computer Science;H. Dierks,1997
4. Ehrig, H., Engels, G., Kreowski, H.-J., Rozenberg, G. (eds.): Handbook on Graph Grammars: Applications, vol. 2. World Scientific, Singapore (1999) (to appear)
5. Engels, G., Schürr, A.: Encapsulated Hierachical Graphs, Graph Types, and Meta Types. In: Corradini, A., Montanari, U. (eds.) SEGRAGRA 1995, Workshop on Graph Rewriting and Computation. Electronic Notes in Theoretical Computer Science, pp. 75-84 (1995)