D. Kauri, B. Oktavia, T. K. Sari, and M. Khair, “Optimum Condition of Ni2+ Cation Desorption from Adsorbent Sulfonate-modified Silica gel-GPTMS”, J. Pijar.MIPA, vol. 19, no. 5, pp. 906–910, Sep. 2024.