Baba, A. A., O. O. Olumodeji, F. A. Adekola, M. Lawa, and A. S. Aremu. “Quantitative Leaching of a Spent Cell Phone Printed Circuit Board by Hydrochloric Acid”. Metallurgical and Materials Engineering, vol. 20, no. 2, July 2014, pp. 119-30, https://metall-mater-eng.com/index.php/home/article/view/162.