APA (7th ed.) Citation

Heywood, D. I., Cornelius, S., & Carver, S. (1998). An introduction to geographical information systems. Longman.

Chicago Style (17th ed.) Citation

Heywood, D. Ian, Sarah Cornelius, and Steve Carver. An Introduction to Geographical Information Systems. Essex: Longman, 1998.

MLA (9th ed.) Citation

Heywood, D. Ian, et al. An Introduction to Geographical Information Systems. Longman, 1998.