Não informado. (1991). Research and Exploration. National Geographic Society.
Lua i Stíl Chicago (17ú heag.)Não informado. Research and Exploration. Gaithersburg, Md: National Geographic Society, 1991.
Lua MLA (8ú heag.)Não informado. Research and Exploration. National Geographic Society, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.