Soil survey staff. (1990). Keys to soil taxonomy. Blacksburg, Va: Virginia Polytechnic Institute and State University.
शिकागो स्टाइल उद्धरणSoil survey staff. Keys to Soil Taxonomy. Blacksburg, Va: Virginia Polytechnic Institute and State University, 1990.
एमएलए उद्धरणSoil survey staff. Keys to Soil Taxonomy. Blacksburg, Va: Virginia Polytechnic Institute and State University, 1990.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.