APA

Hilty S. L., Brown W. L. & Tudor G. (1986). A guide to the birds of Colombia. Princeton, NJ: Princeton University Press.

Chicago

Hilty Steven L, Brown William L and Tudor Guy. 1986. A guide to the birds of Colombia. Princeton, NJ: Princeton University Press.

Harvard

Hilty S. L., Brown W. L. and Tudor G. (1986). A guide to the birds of Colombia. Princeton, NJ: Princeton University Press.

MLA

Hilty Steven L, Brown William L and Tudor Guy. A guide to the birds of Colombia. Princeton, NJ: Princeton University Press. 1986.