Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.