Treating Enhanced Entity Relationship Models in a Declarative Style. - Norbert Kehrer; Gustaf Neumann (RCLP, 1991)

Business Event Oriented Information Systems Based on Meta Programming. - Norbert Kehrer; Gustaf Neumann (ECAI, 1992)

An EER Prototyping Environment and its Implemetation in a Datalog Language. - Norbert Kehrer; Gustaf Neumann (ER, 1992)