Bruno Martins José Luis Borbinha Gilberto Pedrosa João Gil Nuno Freire Geographically-aware information retrieval for collections of digitized historical maps. 39-42 2007 conf/gir/2007 GIR http://doi.acm.org/10.1145/1316948.1316959 db/conf/gir/gir2007.html#MartinsBPGF07