A population study of penguins
MLA
Richdale, Lancelot Eric. A Population Study of Penguins. Oxford: Clarendon Press, 1957
APA, 7th edition
Richdale, L. Eric. (1957). A population study of penguins. Oxford: Clarendon Press
Chicago, 17th edition
Richdale, Lancelot Eric. A population study of penguins. Oxford: Clarendon Press, 1957