Purnomo, C. W., E. Kesuma, S. K. Wirawan, and H. Hinode. “The Development of Lithium Ion Recovery Method by Activated Carbon and Natural Zeolite-Based Adsorbent”. ASEAN Journal of Chemical Engineering, Vol. 17, no. 1, June 2017, pp. 91-98, https://journal.ugm.ac.id/v3/AJChE/article/view/8962.