Saad, Saiful Azhar, et al. “Carboxylated Adsorbent from Confiscated Cigarette Tobacco for Methylene Blue Removal”. International Journal of Integrated Engineering, vol. 18, no. 3, Apr. 2026, pp. 210-26, https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/21812.