R. Agrawal, A. Borgida, and H. Jagadish. SIGMOD '89: Proceedings of the 1989 ACM SIGMOD international conference on Management of data, page 253--262. New York, NY, USA, ACM Press, (1989)
R. Agrawal, A. Borgida, and H. Jagadish. Proceedings of the 1989 ACM SIGMOD International Conference on Management of Data, Portland, Oregon, May 31 - June 2, 1989, page 253-262. ACM Press, (1989)