Sari MI, Prabu Putri Z, Anggun Sari D, Indah Lestari D. Comparative Study of The Effect of Water Sample Preservation Variations and Spectrophotometer Types on Chemical Oxygen Demand (COD) Testing Results. IJSE [Internet]. 2026 Feb. 6 [cited 2026 Feb. 25];6(1):698-704. Available from: https://ijsenet.com/index.php/IJSE/article/view/393