Eliseo Clementini Paolino Di Felice Krzysztof Koperski Mining multiple-level spatial association rules for objects with a broad boundary. 251-270 2000 34 Data Knowl. Eng. 3 db/journals/dke/dke34.html#ClementiniFK00 http://dx.doi.org/10.1016/S0169-023X(00)00017-3