Paputungan , Mardjan, et al. “Adsorption Power of Activated Charcoal from Coconut Shells on Lead Metal (Pb) in Well Water”. Jurnal Penelitian Pendidikan IPA, vol. 9, no. 11, Nov. 2023, pp. 9270-7, doi:10.29303/jppipa.v9i11.4387.