APA استشهاد

Bernhardsen, T. (1999). Geographic information systems: An introduction (2nd ed.). John Wiley.

استشهاد بنمط شيكاغو

Bernhardsen, Tor. Geographic Information Systems: An Introduction. 2nd ed. New York: John Wiley, 1999.

MLA استشهاد

Bernhardsen, Tor. Geographic Information Systems: An Introduction. 2nd ed. John Wiley, 1999.