Castaldo, N. F., De Seve, K., & Raven-Ellison, D. (2014). Mission: polar bear rescue: All about polar bears and how to save them. National Geographic Society.
Cita Chicago Style (17a ed.)Castaldo, Nancy F., Karen De Seve, y Daniel Raven-Ellison. Mission: Polar Bear Rescue: All About Polar Bears and How to Save Them. Washington, D.C.: National Geographic Society, 2014.
Cita MLA (8a ed.)Castaldo, Nancy F., et al. Mission: Polar Bear Rescue: All About Polar Bears and How to Save Them. National Geographic Society, 2014.
Precaución: Estas citas no son 100% exactas.