Cita APA (7th ed.)

Freedman, R. A., Geller, R. M., & Kaufmann, W. J. (2011). Universe (Ninth edition.). W. H Freeman and Company.

Cita Chicago (17th ed.)

Freedman, Roger A., Robert M. Geller, i William J. Kaufmann. Universe. Ninth edition. New York, USA: W. H Freeman and Company, 2011.

Cita MLA (9th ed.)

Freedman, Roger A., et al. Universe. Ninth edition. W. H Freeman and Company, 2011.