APA (7e ed.) Bronvermelding

Penna, A. N. (2015). The human footprint: A global environmental history (Second edition.). Wiley Blackwell.

Chicago (17e ed.) Bronvermelding

Penna, Anthony N. The Human Footprint: A Global Environmental History. Second edition. Chichester, West Sussex, United Kingdom: Wiley Blackwell, 2015.

MLA (9e ed.) Bronvermelding

Penna, Anthony N. The Human Footprint: A Global Environmental History. Second edition. Wiley Blackwell, 2015.