Carlson, L. M. (2005). William J. Spillman and the birth of agricultural economics. University of Missouri Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCarlson, Laurie M. William J. Spillman and the Birth of Agricultural Economics. Columbia: University of Missouri Press, 2005.
एमएलए (9वां संस्करण) प्रशस्ति पत्रCarlson, Laurie M. William J. Spillman and the Birth of Agricultural Economics. University of Missouri Press, 2005.
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