Não informado. (1974). Journal of Rural Economics and Development. University of Ibadan, Department of Agricultural Extension Services.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Journal of Rural Economics and Development. Ibadan, Nigeria: University of Ibadan, Department of Agricultural Extension Services, 1974.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Journal of Rural Economics and Development. University of Ibadan, Department of Agricultural Extension Services, 1974.
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