U. Hohenstein and G. Engels, “Formal Semantics of an Entity-Relationship Query Language,” in Proceedings of the 9th International Conference on Entity-Relationship Approach (ER 90), Lausanne, Switzerland, 1990, pp. 177–188.

G. Engels, “Elementary Actions on an Extended Entity-Relationship Database,” in Proceedings of the workshop on Graph Grammars and Their Application to Computer Science (1990), Bremen (Germany), 1990, vol. 532, pp. 344–362.

J. Ebert and G. Engels, “Konzepte einer Software-Architektur-Beschreibungssprache,” in Software-Entwicklung: Konzepte, Erfahrungen, Perspektiven, Fachtagung, 1989, Marburg (Germany), 1989, vol. 212, pp. 238–250.

G. Engels, “CADDY-O: Syntaxgestütztes, graphisches Entwerfen konzeptioneller Datenbankschemata,” in Tagungsband GI-Fachtagung “Interaktive Schnittstellen für Informationssysteme”, TU Clausthal, Notizen zu Interaktive Systeme, 1989, vol. 18, pp. 1–16.

G. Engels, U. Hohenstein, K. Hülsmann, P. Löhr-Richter, and H.-D. Ehrich, “CADDY: Computer-Aided Design of Non-Standard Databases,” in Proceedings of the International Conference on System Development Environments &; Factories, Berlin, Germany, 1989.

G. Engels, Benutzerschnittstelle und Architektur der integrierten Datenbankentwurfsumgebung CADDY (Kurzfassung). TU Braunschweig, 1989.

G. Engels and W. Schäfer, Programmentwicklungsumgebungen: Konzepte und Realisierung. Stuttgart: Teubner, 1989.

G. Engels, T. Janning, and W. Schäfer, “A Highly Integrated Tool Set for Program Development Support,” in Proceedings of the conference on ACM SIGSMALL/PC symposium on ACTES (SIGSMALL 1988), Cannes (France), 1988, pp. 1–10.

G. Engels, U. Hohenstein, L. Neugebauer, G. Saake, and H.-D. Ehrich, “Konzeption einer integrierten Datenbank-Entwurfsumgebung,” in Proceedings of DBTA/SI Data Dictionaries und Entwicklungswerkzeuge für Datenbank-Anwendungen, Zürich, Switzerland, 1988, pp. 151–157.

G. Engels, U. Hohenstein, G. Saake, and H.-D. Ehrich, “Auf dem Weg zu einer integrierten Datenbank-Entwurfsumgebung,” in Proceedings of the GI-Workshop on “Sprachspezifische Programmierumgebungen,” 1988, pp. 38–51.

J. Ebert and G. Engels, Ein Konzept zur Beschreibung von Software-Architekturen. EWH Koblenz, 1988.

G. Engels, T. Janning, and W. Schäfer, “Die Benutzerschnittstelle einer integrierten Modula-2 Programmentwicklungsumgebung,” in Proceedings of GI-Workshop Sprachspezifische Programmierumgebungen, Darmstadt, Germany, 1988.

G. Engels and A. Schürr, “A Hybrid Interpreter in a Software Development Environment,” in Proceedings of the 1st European Software Engineering Conference (ESEC ’87), Strasbourg (France), 1987, vol. 289, pp. 80–88.

G. Engels, M. Nagl, and W. Schäfer, “On the Structure of Structure-Oriented Editors for Different Applications,” in Proceedings of the ACM SIGSOFT/SIGPLAN Software Engineering Symposium on Practical Software Development Environments, Palo Alto, USA, 1987, vol. 22, no. 1, pp. 190–198.

G. Engels, C. Lewerentz, and W. Schäfer, “Graph Grammar Engineering: A Software Specification Method,” in Proceedings of the 3rd International Workshop on Graph-Grammars and Their Application to Computer Science, Warrenton, VA (USA), 1987, vol. 291, pp. 186–201.

G. Engels, C. Lewerentz, M. Nagl, and W. Schäfer, “On the Structure of an Incremental and Integrated Software Development Environment,” in Proceedings of the 19th Hawaii International Conference on System Sciences, Hawaii, USA, 1986, vol. 2a, pp. 585–597.

G. Engels and A. Sandbrink, “Experiences with a Hybrid-Interpreter Based on Incremental Compilation Techniques,” in Proceedings of the Workshop on Compiler Compilers and Incremental Compilation Techniques, Bautzen, 1986, vol. 12, pp. 172–184.

G. Engels, Graphen als zentrale Datenstrukturen in einer Software-Entwicklungsumgebung. 1986.

G. Engels and W. Schäfer, “Graph Grammar Engineering: A Method Used for the Development of an Integrated Programming Support Environment,” in Proceedings of the International Joint Conference on Theory and Practice of Software Development (TAPSOFT 1985), Berlin (Germany), 1985, vol. 186, pp. 179–193.

G. Engels and W. Schäfer, “The Design of an Adaptive and Portable Programming Support Environment,” in Proceedings of the International Computing Symposium, Amsterdam (The Netherlands), 1985.