Setiawati, Dita, Yuris Diksy, and Ardina Purnama Tirta. 2025. “Performance Test for COD Determination in Wastewater Using a Closed Reflux Method With a COD Reactor”. Indonesian Journal of Applied Environmental Studies 6 (`1):20-25. https://doi.org/10.33751/injast.v6i`1.5.