H. Ulia, H. Hafnimardiyanti, A. K. Yahya, E. Nurmalasari, A. B. Sahaq, and A. Y. Maulana, “Enhancement of Coal Fly Ash as a Bleaching Adsorbent for Crude Palm Kernel Oil through Physical and Chemical Activation”, CJTK, vol. 13, no. 1, pp. 65–77, Jun. 2026.