TY  - BOOK
AU  - Walford, Nigel
TI  - Geographical Data: Characteristics and Sources
SN  - 0471970859
AV  - G70.212.W3 
PY  - 2002///
CY  - Chichester
PB  - John Wiley and Sons Ltd
KW  - Geographic information systems
N1  - BookData Record
ER  -