APA

Atwater R., Atwater F. & Lawson R. (1938). Mr. Popper's penguins. Boston: Little, Brown and Co.

Chicago

Atwater Richard, Atwater Florence and Lawson Robert. 1938. Mr. Popper's penguins. Boston: Little, Brown and Co.

Harvard

Atwater R., Atwater F. and Lawson R. (1938). Mr. Popper's penguins. Boston: Little, Brown and Co.

MLA

Atwater Richard, Atwater Florence and Lawson Robert. Mr. Popper's penguins. Boston: Little, Brown and Co. 1938.