Day, R. W. (2001). Soil testing manualprocedures, classiffication data, and sampling practices. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Day, Robert W. Soil Testing Manualprocedures, Classiffication Data, and Sampling Practices. McGraw-Hill, 2001.
Lua MLA (8ú heag.)Day, Robert W. Soil Testing Manualprocedures, Classiffication Data, and Sampling Practices. McGraw-Hill, 2001.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.