APA (7th ed.) Citation

Unwin, D., & Dawson, J. A. (1985). Computer programming for geographers. Longman.

Chicago Style (17th ed.) Citation

Unwin, D., and John A. Dawson. Computer Programming for Geographers. London: Longman, 1985.

MLA (9th ed.) Citation

Unwin, D., and John A. Dawson. Computer Programming for Geographers. Longman, 1985.