Não informado. (2004). Oxford Agrarian Studies. University of Oxford, Institute of Agricultural Economics.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Oxford Agrarian Studies. Oxford, Inglaterra: University of Oxford, Institute of Agricultural Economics, 2004.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Oxford Agrarian Studies. University of Oxford, Institute of Agricultural Economics, 2004.
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