"Potassium Efficiency of Different Crops Grown on a Sandy Soil under Controlled Conditions". University of Khartoum Journal of Agricultural Sciences 18, no. 3 (مارس 28, 2023). تاريخ الوصول مايو 25, 2026. https://onlinejournals.uofk.edu/uofkjas/article/view/1930.