International Conference on Entity-Relationship Approach Lausanne, Switzerland, & Kangassalo, H. (1991). Entity-relationship approach, the core of conceptual modelling: Proceedings of the Ninth International Conference on the Entity-Relationship Approach, Lausanne, Switzerland, 8-10 October, 1990. North-Holland : Distributors for the U.S. and Canada, Elsevier Science Pub. Co..
Παραπομπή σε μορφή Chicago (17η εκδ.)International Conference on Entity-Relationship Approach Lausanne, Switzerland, και Hannu Kangassalo. Entity-relationship Approach, the Core of Conceptual Modelling: Proceedings of the Ninth International Conference on the Entity-Relationship Approach, Lausanne, Switzerland, 8-10 October, 1990. Amsterdam ; New York, N.Y., U.S.A. ;: North-Holland : Distributors for the U.S. and Canada, Elsevier Science Pub. Co., 1991.
Παραπομπή σε μορφή MLA (9th εκδ.)International Conference on Entity-Relationship Approach Lausanne, Switzerland, και Hannu Kangassalo. Entity-relationship Approach, the Core of Conceptual Modelling: Proceedings of the Ninth International Conference on the Entity-Relationship Approach, Lausanne, Switzerland, 8-10 October, 1990. North-Holland : Distributors for the U.S. and Canada, Elsevier Science Pub. Co., 1991.