- Hartmut Ehrig, Robert A. Kowalski, Giorgio Levi, Ugo Montanari, editors, TAPSOFT 87: Proceedings of the International Joint Conference on Theory and Practice of Software Development, Pisa, Italy, March 23-27, 1987, Volume 2: Advanced Seminar on Foundations of Innovative Software Development II and Colloquium on Functional and . Volume 250 of Lecture Notes in Computer Science, Springer, 1987.
- Hartmut Ehrig, Robert A. Kowalski, Giorgio Levi, Ugo Montanari, editors, TAPSOFT 87: Proceedings of the International Joint Conference on Theory and Practice of Software Development, Pisa, Italy, March 23-27, 1987, Volume 1: Advanced Seminar on Foundations of Innovative Software Development I and Colloquium on Trees in Algebra. Volume 249 of Lecture Notes in Computer Science, Springer, 1987.