Suryaningrum, L., and R. Adriyani. “Parameter Analysis of COD and BOD Liquid Waste at Sidoarjo Steel Company 2022”. Jurnal EduHealth, vol. 14, no. 04, Nov. 2023, pp. 270-3, https://ejournal.seaninstitute.or.id/index.php/healt/article/view/2785.