Beeby, A., & Brennan, A. (2008). First ecology: Ecological principles and environmental issues (3rd ed.). Oxford University Press.

Beeby, Alan, and Anne-Maria Brennan. First Ecology: Ecological Principles and Environmental Issues. 3rd ed. Oxford: Oxford University Press, 2008.

Beeby, Alan, and Anne-Maria Brennan. First Ecology: Ecological Principles and Environmental Issues. 3rd ed. Oxford University Press, 2008.