APA

Watts D., . (1971). Principles of biogeography. New York: McGraw-Hill.

Chicago

Watts David, . 1971. Principles of biogeography. New York: McGraw-Hill.

Harvard

Watts D., . (1971). Principles of biogeography. New York: McGraw-Hill.

MLA

Watts David, . Principles of biogeography. New York: McGraw-Hill. 1971.