Comparative Study on Extraction of Humic Acid from Pakistani Coal Samples by Oxidizing the Samples with Hydrogen Peroxide. ASEAN Journal of Science and Engineering, [S. l.], v. 2, n. 1, p. 1–8, 2022. DOI: 10.17509/ajse.v2i1.35521. Disponível em: https://ajse.upi.edu/index.php/ajse/article/view/67. Acesso em: 16 oct. 2026.