00423nam a2200145 a 450000500170000002000150001708200160003210000180004824500810006626000280014730000190017549000520019463000130024663000180025920251203090544.0  a0198545924  a333.73bBUR  aBurrough P.A.  aPrinciples of geographical information systems for land resources assessment  aOxfordbClarendonc1986  axiv,193p, 23cm  aMonographs on soil and resources surveydNo. 12  aLand use  aSoil resource