“The Feasibility of using Natural Rocks as Sources of Zinc and Cobalt Inlivestock Feeding in Ethiopia”, GJSFR, vol. 15, no. D9, pp. 1–5, Jan. 2016, Accessed: Aug. 13, 2026. [Online]. Available: https://www.journalofscience.org/index.php/GJSFR/article/view/1685