SAGAN, C. (1982). Pustaka ilmu life: Planet. Tira Pustaka.
Lua i Stíl Chicago (17ú heag.)SAGAN, Carl. Pustaka Ilmu Life: Planet. Tira Pustaka, 1982.
Lua MLA (8ú heag.)SAGAN, Carl. Pustaka Ilmu Life: Planet. Tira Pustaka, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.