Παραπομπή σε μορφή APA (7η εκδ.)

Wills, I. R. (2007). Economics and the environment: A signalling and incentives approach (2nd ed.). Allen & Unwin.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Wills, Ian R. Economics and the Environment: A Signalling and Incentives Approach. 2nd ed. St. Leonards, NSW: Allen & Unwin, 2007.

Παραπομπή σε μορφή MLA (8th εκδ.)

Wills, Ian R. Economics and the Environment: A Signalling and Incentives Approach. 2nd ed. Allen & Unwin, 2007.