Sagan, C., & Leonard, J. N. 1. j. a. (1972). Planets. Time-Life Books.
Lua i Stíl Chicago (17ú heag.)Sagan, Carl, agus Jonathan Norton 1903- joint auth Leonard. Planets. New York: Time-Life Books, 1972.
Lua MLA (9ú heag.)Sagan, Carl, agus Jonathan Norton 1903- joint auth Leonard. Planets. Time-Life Books, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.