D. Harel, H. Kugler, and A. Pnueli. Formal Methods in Software and Systems Modeling: Essays Dedicated to Hartmut Ehrig on the Occasion of His 60th Birthday, page 309--324. Department of Computer Science and Applied Mathematics, The Weizmann Institute of Science, Rehovot, Israel, Springer, (2005)
D. Harel, H. Kugler, and A. Pnueli. Formal Methods in Software and Systems Modeling: Essays Dedicated to Hartmut Ehrig on the Occasion of His 60th Birthday, page 309--324. Department of Computer Science and Applied Mathematics, The Weizmann Institute of Science, Rehovot, Israel, Springer, (2005)
W. Kügler. Europäische Hochschulschriften: Reihe 13, Französische Sprache und Literatur Lang, Frankfurt/M., Berlin, Bern, Bruxelles, New York, Wien, (1984)