Gaya APA
Longley, P, A. et al (2005).
Geographical information systems: principles, techniques, management, and applications (Second edition).
New Jersey:
John Wiley & Sons Inc.
Gaya MLA
Longley, Paul, A.. et al.
"Geographical information systems: principles, techniques, management, and applications".
Second edition
New Jersey:
John Wiley & Sons Inc,
2005.
Text.