Não informado. (1945). Down to earth: A review of agricultural chemical progress. Down Chemical, Agricultural Products Department.
Lua i Stíl Chicago (17ú heag.)Não informado. Down to Earth: A Review of Agricultural Chemical Progress. Midland, Mich: Down Chemical, Agricultural Products Department, 1945.
Lua MLA (8ú heag.)Não informado. Down to Earth: A Review of Agricultural Chemical Progress. Down Chemical, Agricultural Products Department, 1945.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.