Παραπομπή APA

Malthus, T., & Pullen, J. (1989). Principles of Political Economy. Cambridge University Press.

Παραπομπή Chicago Style

Malthus, T.R, και John Pullen. Principles of Political Economy. Cambridge: Cambridge University Press, 1989.

Παραπομπή MLA

Malthus, T.R, και John Pullen. Principles of Political Economy. Cambridge University Press, 1989.