Cita APA (7th ed.)

Heywood, I., Cornelius, S., & Carver, S. (1998). An introduction to geographical information systems. Prentice-Hall.

Cita Chicago (17th ed.)

Heywood, Ian, Sarah Cornelius, i Steve Carver. An Introduction to Geographical Information Systems. Upper Saddle River: Prentice-Hall, 1998.

Cita MLA (9th ed.)

Heywood, Ian, et al. An Introduction to Geographical Information Systems. Prentice-Hall, 1998.