5Guttman A. R-trees:A Dynamic Index Structure for Spatial Searching. Prec. ACM SIGMOD[ J]. 1984:47 -57.
6Bechmann N,Kriegel H P,Schneider R,et al. The R ^* tree:An Eficient and Robust Access Method for Points and Rectangles. Proc. ACMS IGMOD [ C ]. Atlantic City, USA, 1990:322 - 331.
7Sellis T, Roussopoulos N, Faloutsos C. The R -tree : A Dynamic Index for Multidimensional Objects. Proc. 13th Int. Conf. on Very Large Databases [ C ]. Brighton, U. K. , 1987:507 - 518.
8Finkeland R A, Bentley J L. Quadtrees: A data structure for retrieval on Compositive keys. Acta Informatic, 1974,4 : 1 - 9.
9Guttman A. R-tree: A dynamic index structure for spa- tial searching[C]//Proceedings of the ACM SIGMOD International Conference on Management of Data. Bos- ton, US, 1984 : 47- 57.