Não informado. (1956). Smithsonian contributions to astrophysics. Smithsonian Institution.
Lua i Stíl Chicago (17ú heag.)Não informado. Smithsonian Contributions to Astrophysics. Washington: Smithsonian Institution, 1956.
Lua MLA (8ú heag.)Não informado. Smithsonian Contributions to Astrophysics. Smithsonian Institution, 1956.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.