00330nam a2200121 a 450000500170000002000150001708200170003210000210004924500510007026000420012130000210016370000240018420251203110044.0  a0198233655  a910.285bBUR  aBurrough Peter A  aPrinciples of geographical information systems  aOxfordbOxford University Pressc1998  axiii,333p.c22cm  aMcDonnel, Rachael A