Não informado. (1972). Agricultural engineer. Institution of Agricultural Engineers.
Lua i Stíl Chicago (17ú heag.)Não informado. Agricultural Engineer. Bedford, Inglaterra: Institution of Agricultural Engineers, 1972.
Lua MLA (8ú heag.)Não informado. Agricultural Engineer. Institution of Agricultural Engineers, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.