Cita APA (7th ed.)

Heywood, I., Cornelius, S., & Carver, S. (2002). An introduction to Geographical Information Systems (2nd ed.). Pearson Education Limited.

Cita Chicago (17th ed.)

Heywood, Ian, Sarah Cornelius, i Steve Carver. An Introduction to Geographical Information Systems. 2nd ed. Harlow, England: Pearson Education Limited, 2002.

Cita MLA (9th ed.)

Heywood, Ian, et al. An Introduction to Geographical Information Systems. 2nd ed. Pearson Education Limited, 2002.