Hohenstein, Uwe, and Gregor Engels. “Formal Semantics of an Entity-Relationship Query Language.” Proceedings of the 9th International Conference on Entity-Relationship Approach (ER 90), Lausanne, Switzerland, ER Institute, 1990, pp. 177–88.

Engels, Gregor. “Elementary Actions on an Extended Entity-Relationship Database.”http://dx.doi.org/10.1007/BFb0017372__Proceedings of the Workshop on Graph Grammars and Their Application to Computer Science (1990), Bremen (Germany), vol. 532, Springer, 1990, pp. 344–62, doi:http://dx.doi.org/10.1007/BFb0017372.

Ebert, Jürgen, and Gregor Engels. “Konzepte Einer Software-Architektur-Beschreibungssprache.” Software-Entwicklung: Konzepte, Erfahrungen, Perspektiven, Fachtagung, 1989, Marburg (Germany), vol. 212, Springer, 1989, pp. 238–50.

Engels, Gregor. “CADDY-O: Syntaxgestütztes, Graphisches Entwerfen Konzeptioneller Datenbankschemata.” Tagungsband GI-Fachtagung “Interaktive Schnittstellen Für Informationssysteme”, TU Clausthal, Notizen Zu Interaktive Systeme, vol. 18, 1989, pp. 1–16.

Engels, Gregor, et al. “CADDY: Computer-Aided Design of Non-Standard Databases.” Proceedings of the International Conference on System Development Environments &; Factories, Berlin, Germany, Pitman Publishing, 1989.

Engels, Gregor. Benutzerschnittstelle Und Architektur Der Integrierten Datenbankentwurfsumgebung CADDY (Kurzfassung). TU Braunschweig, 1989.

Engels, Gregor, and Wilhelm Schäfer. Programmentwicklungsumgebungen: Konzepte Und Realisierung. Teubner, 1989.

Engels, Gregor, et al. “A Highly Integrated Tool Set for Program Development Support.”http://dx.doi.org/10.1145/62453.62454__Proceedings of the Conference on ACM SIGSMALL/PC Symposium on ACTES (SIGSMALL 1988), Cannes (France), ACM Press, 1988, pp. 1–10, doi:http://dx.doi.org/10.1145/62453.62454.

Engels, Gregor, et al. “Konzeption Einer Integrierten Datenbank-Entwurfsumgebung.” Proceedings of DBTA/SI Data Dictionaries Und Entwicklungswerkzeuge Für Datenbank-Anwendungen, Zürich, Switzerland, Verlag der Fachvereine an den Schweiz. Hochschulen und Techniken, 1988, pp. 151–57.

Engels, Gregor, et al. “Auf Dem Weg Zu Einer Integrierten Datenbank-Entwurfsumgebung.” Proceedings of the GI-Workshop on “Sprachspezifische Programmierumgebungen,” edited by Gregor Engels et al., G. Snelting, 1988, pp. 38–51.

Ebert, Jürgen, and Gregor Engels. Ein Konzept Zur Beschreibung von Software-Architekturen. EWH Koblenz, 1988.

Engels, Gregor, et al. “Die Benutzerschnittstelle Einer Integrierten Modula-2 Programmentwicklungsumgebung.” Proceedings of GI-Workshop Sprachspezifische Programmierumgebungen, Darmstadt, Germany, 1988.

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

Engels, Gregor, et al. “On the Structure of Structure-Oriented Editors for Different Applications.” Proceedings of the ACM SIGSOFT/SIGPLAN Software Engineering Symposium on Practical Software Development Environments, Palo Alto, USA, vol. 22, no. 1, ACM SIGPLAN Notices, 1987, pp. 190–98.

Engels, Gregor, et al. “Graph Grammar Engineering: A Software Specification Method.”dx.doi.org/10.1007/3-540-18771-5__Proceedings of the 3rd International Workshop on Graph-Grammars and Their Application to Computer Science, Warrenton, VA (USA), vol. 291, Springer, 1987, pp. 186–201, doi:dx.doi.org/10.1007/3-540-18771-5.

Engels, Gregor, et al. “On the Structure of an Incremental and Integrated Software Development Environment.” Proceedings of the 19th Hawaii International Conference on System Sciences, Hawaii, USA, vol. 2a, 1986, pp. 585–97.

Engels, Gregor, and Andrea Sandbrink. “Experiences with a Hybrid-Interpreter Based on Incremental Compilation Techniques.” Proceedings of the Workshop on Compiler Compilers and Incremental Compilation Techniques, Bautzen, vol. 12, Berlin(Ost): Akademie der Wissenschaften der DDR, 1986, pp. 172–84.

Engels, Gregor. Graphen Als Zentrale Datenstrukturen in Einer Software-Entwicklungsumgebung. 1986.

Engels, Gregor, and Wilhelm Schäfer. “Graph Grammar Engineering: A Method Used for the Development of an Integrated Programming Support Environment.” Proceedings of the International Joint Conference on Theory and Practice of Software Development (TAPSOFT 1985), Berlin (Germany), vol. 186, Springer, 1985, pp. 179–93.

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