Não informado. (1987). Nigerian Journal of Palms and Oil Seeds. Nigerian Institute for Oil Palm Research.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Nigerian Journal of Palms and Oil Seeds. Benin City, Nigeria: Nigerian Institute for Oil Palm Research, 1987.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Nigerian Journal of Palms and Oil Seeds. Nigerian Institute for Oil Palm Research, 1987.
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