Abu Bakar Sidik, Dilaeleyana, et al. “The Photocatalytic Activity of Green Zinc Oxide Nanoparticles in The Treatment of Aerobically Palm Oil Mill Effluent”. Journal of Science and Technology, vol. 15, no. 1, July 2023, pp. 7-15, https://publisher.uthm.edu.my/ojs/index.php/JST/article/view/13619.