TY  - BOOK
AU  - Burrough P A
TI  - Principles of geographical information systems for
T2  - Monographs On Soil And Resources Survey. 12
U1  - U673:(D6,9(B), M6 
PY  - 1987///
CY  - Oxford
PB  - Clarendon Press         
KW  - Geography
N1  - Appendix P 176-86
ER  -