Software Specification by Graph Grammars
M. Nagl, G. Engels, R. Gall, W. Schäfer, in: Proceedings of the 2nd International Workshop on Graph-Grammars and Their Application to Computer Science, Osnabrück (Germany), Springer, Berlin/Heidelberg, 1983, pp. 267–287.
LibreCat: /record/8255
DOI: dx.doi.org/10.1007/BFb0000113

Software Specification Using Graph Grammars
G. Engels, R. Gall, M. Nagl, W. Schäfer, Computing 31 (1983) 317–346.
LibreCat: /record/7411
DOI: http://dx.doi.org/10.1007/BF02251236

An Operational Semantics for Specifications of Abstract Data Types with Error Handling
G. Engels, U. Pletat, H.-D. Ehrich, Acta Informatica 9 (1983) 235–254.
LibreCat: /record/7412
DOI: http://dx.doi.org/10.1007/BF00265557

Specification of a Programming Support Environment by Graph Grammars
G. Engels, W. Schäfer, in: Proceedings of the Conference on Graphtheoretic Concepts in Computer Science (WG), München (Germany), Hanser, München/Leipzig, 1982, pp. 47–62.
LibreCat: /record/7811

An Operational Approach to Conditional Algebraic Specifications
U. Pletat, G. Engels, H.-D. Ehrich, in: Proceedings of the 7eme Colloque Sur Les Arbres En Algebre et En Programmation, Lille (France), 1982, pp. 254–270.
LibreCat: /record/7812

Handling Errors and Exceptions in the Algebraic Specifications of Data Types
G. Engels, U. Pletat, H.-D. Ehrich, Handling Errors and Exceptions in the Algebraic Specifications of Data Types, University of Osnabrück, 1981.
LibreCat: /record/8184

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.
LibreCat: /record/8185