Sulieman Ahmed Gasim El Said, Hatil Hashim EL-Kamali, and Sara Ahmed Saad. “Analysis of Physico-Chemical and Macro Element Concentration in Soils of Six Farmlands in Khartoum State, Central Sudan”. Journal of The Faculty of Science and Technology, no. 7, Aug. 2021, pp. 117 -24, doi:10.52981/jfst.vi7.964.