Sihombing JL, Herlinawati H, Pulungan AN, Kembaren A, Saragih G, Harmileni H, et al. Unveiling ZrO2/natural zeolite catalytic performance on hydrocracking palm oil mill effluent residue. J.Pendidik.Kim [Internet]. 2023 Aug. 27 [cited 2025 Aug. 8];15(2):100-1. Available from: https://jurnal.unimed.ac.id/2012/index.php/jpk/article/view/43324