@inproceedings{Boulicaut00approximation, author = {Boulicaut, Jean-Fran�ois and Bykowski, Artur and Rigotti, Christophe}, booktitle = {PKDD}, ee = {http://link.springer.de/link/service/series/0558/bibs/1910/19100075.htm}, interhash = {bcaa8a570d6b987b6171c4b7aff7cacd}, intrahash = {7235b0afd136e65466a215df38510a38}, pages = {75-85}, title = {Approximation of Frequency Queris by Means of Free-Sets.}, url = {http://dblp.uni-trier.de/db/conf/pkdd/pkdd2000.html#BoulicautBR00}, year = 2000 }