Otenyo Makonjio Philip, et al. “Efficiency of Pumice-Sand Granular Filter in Removing Effluent Wastes in Shirere Wastewater Treatment Plant in Kakamega County, Kenya”. American Scientific Research Journal for Engineering, Technology, and Sciences, vol. 96, no. 1, Oct. 2023, pp. 1-28, https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/9500.