Jonathan, S., E. F. Adebayo, M. Joseph, and S. K. Tarki. 2023. “PRODUCTIVITY MEASUREMENTS IN SOLE COWPEA FARMING: A CASE STUDY OF NORTHERN AGRICULTURAL ZONE OF ADAMAWA STATE, NIGERIA”. International Journal of Global Affairs, Research and Development 1 (1):97-103. https://ijgard.com/index.php/ijgard/article/view/12.