Sagan, C., & Agel, p. J. (1975). The cosmic connection. Coronet Books.
Lua i Stíl Chicago (17ú heag.)Sagan, Carl, agus prod. Jerome Agel. The Cosmic Connection. Coronet Books, 1975.
Lua MLA (8ú heag.)Sagan, Carl, agus prod. Jerome Agel. The Cosmic Connection. Coronet Books, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.