Gaya APA

Heywood, I., Steve, I, C, S, I, C. (2011). An introduction to Geographical Information Systems (4). London: Pearson International.

Gaya MLA

Heywood, Ian., Steve, I., Cornelius,, Sarah, II., Carver,. "An introduction to Geographical Information Systems". 4 London: Pearson International, 2011. .