.A.S. Jeghata, H, and N. M. Muhawish. 2021. “Effect of Three Tillage Systems, Levels of Plant Residues and Type of Crop on Some Physical Properties and Organic Carbon Fractions in a Gypsiferous Soil”. College of Basic Education Research Journal 17 (1):929-54. https://doi.org/10.33899/berj.2021.167750.