Osman, N. S., et al. “Synthesis of Oil Palm Frond (OPF) Based Silica Nanomaterial via Sol-Gel Method With Enhanced Phenol Removal ”. Journal of Chemical Engineering and Industrial Biotechnology, vol. 7, no. 2, Nov. 2021, pp. 20-26, https://doi.org/10.15282/jceib.v7i2.6917.