Troeh, F. R., Donahue, R. L., & Hobbs, J. A. (1980). Soil and water conservation for productivity and environmental protection. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Troeh, Frederick R., Roy L. Donahue, agus J. Arthur Hobbs. Soil and Water Conservation for Productivity and Environmental Protection. Englewood Cliffs, N.J: Prentice-Hall, 1980.
Lua MLA (9ú heag.)Troeh, Frederick R., et al. Soil and Water Conservation for Productivity and Environmental Protection. Prentice-Hall, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.