Badilla, D. B., P. A. Gostomski, and M. L. P. Dalida. “Influence of Water Content on Biofiltration Performance”. ASEAN Journal of Chemical Engineering, Vol. 10, no. 2, Dec. 2010, pp. 31-39, https://dev.journal.ugm.ac.id/v3/AJChE/article/view/8069.