Mehari, Beraki B., et al. “Preliminary Assessment of Low Cost Local Sorbent Materials for Water Defluoridation in Keren, Eritrea”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 18, no. 1, Aug. 2014, pp. 45-58, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/2581.