Dyfyniad APA

Worrall, L. (1990). Geographic information systems: Developments and applications. Belhaven Press.

Dyfyniad Arddull Chicago

Worrall, Les. Geographic Information Systems: Developments and Applications. London ; New York: Belhaven Press, 1990.

Dyfyniad MLA

Worrall, Les. Geographic Information Systems: Developments and Applications. Belhaven Press, 1990.

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