Stefano Spaccapietra Salvatore T. March Yahiko Kambayashi Conceptual Modeling - ER 2002, 21st International Conference on Conceptual Modeling, Tampere, Finland, October 7-11, 2002, Proceedings ER Lecture Notes in Computer Science 2503 Springer 2002 3-540-44277-4 db/conf/er/er2002.html