LAL, R. (1976). Soil physical properties and crop production in the tropis. John Wiley & Sons.
Lua i Stíl Chicago (17ú heag.)LAL, R. Soil Physical Properties and Crop Production in the Tropis. John Wiley & Sons, 1976.
Lua MLA (8ú heag.)LAL, R. Soil Physical Properties and Crop Production in the Tropis. John Wiley & Sons, 1976.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.