(1973). Soil Testing And Plant Analysis. Soil Science Society of Americ.
Lua i Stíl Chicago (17ú heag.)Soil Testing And Plant Analysis. Soil Science Society of Americ, 1973.
Lua MLA (8ú heag.)Soil Testing And Plant Analysis. Soil Science Society of Americ, 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.