1. Kamel I, and Faloutsos C., “On packing R-trees”, Proceeding of the 2nd conference on information and knowledge. management (CIKM), Washington DC. Pp.490-499, November1993 .
2. Abel D., “Spatial Join Strategies in Distributed Spatial DBMS”, Proceedings of fourth international symposium on Large. Spatial Databases, Maine, pp.348-367, August 1995 .
3. Feng Lu, and Chenghu Zhou., “A GIS spatial indexing approach based on Hilbert ordering code”, cad$cg, Vol 13, No. 5, pp. 424-429, May. 2001 .
4. J. Ronald Eastman, Michele Fulk, and JamesToledano: The GIS Handbook. Clark University, 2003 .
5. Spatial Databases: Authors: Shashi Shekhar and Sanjay Chawla. Publisher: Prentice Hall, 2003 .