National Fertilizer Development Center. (1973). Fertilizer trends. Washington, D.C: National Fertilizer Development Center.
शिकागो स्टाइल उद्धरणNational Fertilizer Development Center. Fertilizer Trends. Washington, D.C: National Fertilizer Development Center, 1973.
एमएलए उद्धरणNational Fertilizer Development Center. Fertilizer Trends. Washington, D.C: National Fertilizer Development Center, 1973.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.