@inproceedings{KKM93a,
 author = {Keim, Daniel A. and Kriegel, Hans-Peter and Miethsam, Andreas},
 booktitle = {Proc. 4th Int. Conf. on Database and Expert Systems Applications (DEXA'93), Prague, Czech Republic},
 pages = {325--336},
 title = {Object-Oriented Querying of Existing Relational Databases},
 year = {1993}
}