Hartmut Ehrig, Hans-Jörg Kreowski, Peter Padawitz: Stepwise Specification and Implementation of Abstract Data Types. In Proc. International Conference on Automata, Languages and Programming (Udine, July 1978), volume 62 of Lecture Notes in Computer Science, pages 205-226. Springer, 1978.
Hartmut Ehrig, Hans-Jörg Kreowski, Andrea Maggiolo-Schettini, Barry K. Rosen, Jozef Winkowski: Deriving Structures from Structures. In Proc. 7th International Symposium on Math. Foundations of Computer Science (Zakopane, 1978), volume 64 of Lecture Notes in Computer Science, pages 177-190. Springer, 1978.
Hartmut Ehrig, Hans-Jörg Kreowski, Herbert Weber: Algebraic Specification Schemes for Data Base Systems. In Proc. 4th International Conference on Very Large Data Bases (Berlin, Sept. 1978), pages 427-440. 1978.
Hans-Jörg Kreowski: Manipulationen von Graphmanipulationen. Univ. Berlin, 1978. Dissertation, Fachbereich Informatik.
