E. Prasetyo, H. Sudibyo, and W. Budhijanto, “Determination of the Optimum Hydraulic Retention Time in Two-Stage Anaerobic Fluidized Bed Bioreactor for Landfill Leachate Treatment”, J. Eng. Technol. Sci., vol. 49, no. 3, pp. 388-399, Aug. 2017.