Nature... (1971). Nature science annual. Time Life Books.
Lua i Stíl Chicago (17ú heag.)Nature... Nature Science Annual. Time Life Books, 1971.
Lua MLA (8ú heag.)Nature... Nature Science Annual. Time Life Books, 1971.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.