Não informado. (1958). Crops and soils. American Society of Agronomy.
Lua i Stíl Chicago (17ú heag.)Não informado. Crops and Soils. Madison, Wis: American Society of Agronomy, 1958.
Lua MLA (8ú heag.)Não informado. Crops and Soils. American Society of Agronomy, 1958.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.