Opheim. The Future of Family Farms. University of Iowa Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रOpheim. The Future of Family Farms. University of Iowa Press.
एमएलए (9वां संस्करण) प्रशस्ति पत्रOpheim. The Future of Family Farms. University of Iowa Press.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.