1. R. Agrawal and R. Srikant. Fast algorithms for mining association rules. In Proc. 1994 Int. Conf. VLDB, pp. 487–499, Santiago, Chile, Sept. 1994.
2. R. Agrawal, T. Imielinski, and A. Swami. Mining association rules between sets of items in large databases. In Proc. 1993 ACM-SIGMOD Int. Conf. Management of Data, pp. 207–216, Washington, D.C., May 1993.
3. W. G. Aref, and H. Samet. Optimization Strategies for Spatial Query Processing. In Proc. 17th Int. Conf. VLDB, Barcelona, Spain, pp. 81–90, Sept. 1991.
4. T. Brinkhoff, H. P. Kriegel, B. Seege. Efficient Processing of Spatial Joins Using R-trees. In Proc. 1993 ACM-SIGMOD Conf. Management of Data, Washington, D.C. pp. 237–246, May 1993.
5. T. Brinkhoff, H. P. Kriegel, R. Schneider, B. Seege. Multistep Processing of Spatial Joins. In Proc. 1994 ACM-SIGMOD Conf. Management of Data, Minneapolis, Minnesota, pp. 197–208, May 1994.