János Demetrovics Gyula O. H. Katona Dezsö Miklós Bernhard Thalheim On the Number of Independent Functional Dependencies. 83-91 2006 conf/foiks/2006 FoIKS http://dx.doi.org/10.1007/11663881_6 db/conf/foiks/foiks2006.html#DemetrovicsKMT06