Heywood, I., Cornelius, S., & Carver, S. (2003). An Introduction to Geographical Information Systems (2nd ed.). Pearson Education (Singapore) Pte. Ltd.
Citazione stile Chigago Style (17a edizione)Heywood, Ian, Sarah Cornelius, e Steve Carver. An Introduction to Geographical Information Systems. 2nd ed. Delhi: Pearson Education (Singapore) Pte. Ltd, 2003.
Citatione MLA (9a ed.)Heywood, Ian, et al. An Introduction to Geographical Information Systems. 2nd ed. Pearson Education (Singapore) Pte. Ltd, 2003.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.