Hema, M., and K. Srinivasan. “Evaluation of Coconut Oilcake Carbon As Absorbent for Nickel Ion: Equilibrium and Kinetic Studies”. Asian Journal of Chemistry, vol. 22, no. 4, Mar. 2010, pp. 2965-81, https://asianpubs.org/index.php/ajchem/article/view/11504.