Rosli, Mohd Arif, et al. “Performance of Fixed Bed Column Study for The Removal of Nickel and Rhodamine B by Low Cost Hydroxyapatite Alginate Composite Bead Adsorbent”. Progress in Engineering Application and Technology, vol. 1, no. 1, Dec. 2020, pp. 70-78, https://publisher.uthm.edu.my/periodicals/index.php/peat/article/view/118.