Atwater, R. (2011). Mr. popper's penguins. Open Road Media Teen & Tween.
Cita Chicago Style (17a ed.)Atwater, Richard. Mr. Popper's Penguins. New York: Open Road Media Teen & Tween, 2011.
Cita MLA (8a ed.)Atwater, Richard. Mr. Popper's Penguins. Open Road Media Teen & Tween, 2011.
Precaución: Estas citas no son 100% exactas.