Choudhary, VK, and P Kumar. “Nutrient Budgeting, Economics and Energetics of Cowpea under Potassium and Phosphorus Management”. SAARC Journal of Agriculture 11, no. 2 (March 21, 2014): 129-140. Accessed August 4, 2020. https://www.banglajol.info/index.php/SJA/article/view/18408.