O'Connor, R. J., Shrubb, M., & Watson, D. (1986). Farming & birds. Cambridge University Press.
Cita Chicago (17th ed.)O'Connor, Raymond J., Michael Shrubb, i Donald Watson. Farming & Birds. Cambridge [Cambridgeshire] ; New York: Cambridge University Press, 1986.
Cita MLA (8th ed.)O'Connor, Raymond J., et al. Farming & Birds. Cambridge University Press, 1986.
Atenció: Aquestes cites poden no estar 100% correctes.