Cholillah, Vidya Nur. “IDENTIFICATION OF FUNCTIONAL GROUPS IN SLUDGE 120C OF AMMONIA IB FACTORY PT PETROKIMIA GRESIK BY ATR-FTIR METHOD”. Unesa Journal of Chemistry, vol. 14, no. 1, Jan. 2025, pp. 15-19, doi:10.26740/ujc.v14n1.p15-19.