APA (7th ed.) Citation

Castle, G. H. (1993). Profiting from a geographic information system. GIS World.

Chicago Style (17th ed.) Citation

Castle, Gilbert H. Profiting from a Geographic Information System. Ft. Collins, Colo.: GIS World, 1993.

MLA (9th ed.) Citation

Castle, Gilbert H. Profiting from a Geographic Information System. GIS World, 1993.

Warning: These citations may not always be 100% accurate.