1. Adewuyi, Y. G. (2001). Reviews-sonochemistry: Environmental science and engineering applications. Industrial & Engineering Chemistry Research, 40(22), 4681–4715.
2. Ahmaruzzaman, M. (2010). A review on the utilization of fly ash. Progress in Energy and Combustion Science, 36(3), 327–363.
3. Akcil, A., & Koldas, S. (2006). Acid mine drainage (AMD): Causes, treatment and case studies. Journal of Cleaner Production, 14, 1139–1145.
4. Al-Anber, Z. A., & Al-Anber, M. A. S. (2008). Thermodynamics and kinetic studies of iron(III) adsorption by olive cake in a batch system. Journal of the Mexican Chemical Society, 52(2), 108–115.
5. American Public Health Association (APHA). (1998). Acidity (2310)/titration method. In L. S. Clesceri, A. E. Greenberg, & A. D. Eaton (Eds.), Standard methods for the examination of water and wastewater (20th ed., pp. 2.24–2.26). Washington, DC: American Public Health Association.