Vítor Santos Costa Ashwin Srinivasan Rui Camacho Hendrik Blockeel Bart Demoen Gerda Janssens Jan Struyf Henk Vandecasteele Wim Van Laer Query Transformations for Improving the Efficiency of ILP Systems. 465-491 2003 4 Journal of Machine Learning Research http://www.jmlr.org/papers/v4/costa03a.html db/journals/jmlr/jmlr4.html#CostaSCBDJSVL03