TY  - BOOK
AU  - Walford,Nigel
TI  - Geographical data: characteristics and sources 
SN  - 0471970859 (alk. paper)
AV  - G70.212 .W35 2002
U1  - 910/.285/57 21
PY  - 2002///
CY  - West Sussex, England
PB  - John Wiley
KW  - Geographic information systems
N1  - Incluye referencias bibliográficas  (p. [245]-258) and index
UR  - http://www.loc.gov/catdir/toc/wiley021/2001046626.html
ER  -