Guy De Tré Slawomir Zadrozny Tom Matthé Janusz Kacprzyk Antoon Bronselaer Dealing with Positive and Negative Query Criteria in Fuzzy Database Querying. 593-604 2009 FQAS http://dx.doi.org/10.1007/978-3-642-04957-6_51 conf/fqas/2009 db/conf/fqas/fqas2009.html#TreZMKB09