Walid G. Aref, Daniel Barbará, Stephen Johnson, Sharad Mehrotra. Efficient Processing of Proximity Queries for Large Databases. In Philip S. Yu, Arbee L. P. Chen, editors, Proceedings of the Eleventh International Conference on Data Engineering, March 6-10, 1995, Taipei, Taiwan. pages 147-154, IEEE Computer Society, 1995. [doi]