Dyfyniad APA

Sagan, C., & Leonard, J. N. 1. j. a. (1972). Planets. Time-Life Books.

Dyfyniad Arddull Chicago

Sagan, Carl, and Jonathan Norton 1903- joint auth Leonard. Planets. New York: Time-Life Books, 1972.

Dyfyniad MLA

Sagan, Carl, and Jonathan Norton 1903- joint auth Leonard. Planets. Time-Life Books, 1972.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.