Freedman, R. A., Keller, R. M., & Kaufmann, W. J. (2011). Universe (9th ed.). W.H. Freeman and Company.
Chicago Style (17th ed.) CitationFreedman, Roger A., Robert M. Keller, and William J. Kaufmann. Universe. 9th ed. New York: W.H. Freeman and Company, 2011.
MLA (9th ed.) CitationFreedman, Roger A., et al. Universe. 9th ed. W.H. Freeman and Company, 2011.
Warning: These citations may not always be 100% accurate.