Não informado. (1981). Environmental Education and Information. University of Salford.
Lua i Stíl Chicago (17ú heag.)Não informado. Environmental Education and Information. Salford, Inglaterra: University of Salford, 1981.
Lua MLA (8ú heag.)Não informado. Environmental Education and Information. University of Salford, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.