OLANIPEKUN, E., R. A. ODERINDE, and O. K. OKURUMEH. “?DISSOLUTION OF PHOSPHORITE IN DILUTE HYDROCHLORIC ACID SOLUTION”. Biological Sciences - PJSIR, vol. 37, no. 5, Apr. 1994, pp. 183-6, https://v2.pjsir.org/index.php/biological-sciences/article/view/2633.