@inproceedings{Kei99,
 author = {Keim, Daniel A.},
 booktitle = {Proc. ACM SIGMOD Int. Conf. on Management of Data, Philadelphia, PA},
 month = {Jun},
 pages = {419--430},
 publisher = {ACM Press},
 title = {Efficient Geometry--based Similarity Search of 3D Spatial Databases},
 year = {1999}
}