“Sorption of Some Heavy Metal Ions by Chitosan and Chemically Modified Chitosan”, Pakistan Journal of Scientific & Industrial Research, vol. 49, no. 6, pp. 443–447, Dec. 2006, Accessed: Mar. 10, 2026. [Online]. Available: https://www.v2.pjsir.org/index.php/biological-sciences/article/view/1301