Não informado. (1954). Bird Study. British Trust for Ornithology.
Lua i Stíl Chicago (17ú heag.)Não informado. Bird Study. Herts, Inglaterra: British Trust for Ornithology, 1954.
Lua MLA (8ú heag.)Não informado. Bird Study. British Trust for Ornithology, 1954.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.