Não informado. (1980). Soil and water conservation news. U.S. Department of Agriculture, Soil Conservation Service.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Soil and Water Conservation News. Washington: U.S. Department of Agriculture, Soil Conservation Service, 1980.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Soil and Water Conservation News. U.S. Department of Agriculture, Soil Conservation Service, 1980.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.