Παραπομπή APA

Bernhardsen, T. (2011). Geographic information systems: An introduction (3rd ed.). Wiley.

Παραπομπή Chicago Style

Bernhardsen, Tor. Geographic Information Systems: An Introduction. 3rd ed. New Delhi: Wiley, 2011.

Παραπομπή MLA

Bernhardsen, Tor. Geographic Information Systems: An Introduction. 3rd ed. Wiley, 2011.