APA (7th ed.) Citation

De By, R. A. (2001). Principles of geographic information systems: An introductory textbook (2nd ed.). International Institute Aerospace Survey and Earth Sciences (ITC).

Chicago Style (17th ed.) Citation

De By, Rolf A. Principles of Geographic Information Systems: An Introductory Textbook. 2nd ed. Enschede, The Netherlands: International Institute Aerospace Survey and Earth Sciences (ITC), 2001.

MLA (9th ed.) Citation

De By, Rolf A. Principles of Geographic Information Systems: An Introductory Textbook. 2nd ed. International Institute Aerospace Survey and Earth Sciences (ITC), 2001.