Ali, S. A. K., L. D. M. Ibrahim, and H. A. Hussein MSc. “Removal of Lead from Wastewater by Graphene Coated Sand Composite”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 37, no. 1, Jan. 2018, pp. 1-9, https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/8445.