Abdel-Ghani, N. T., Hefny, M., & El-Chaghaby, G. A. F. (2007). Removal of lead from aqueous solution using low cost abundantly available adsorbent. International Journal of Environmental Science and Technology, 4, 67-73. http://dx.doi.org/10.1007/BF03325963
 Adie, D. B., Okuofu, C. A., & Osakwe, C. (2012). Comparative analysis of the adsorption of heavy metals in wastewater using Borrassus Aethiopium and Cocos Nucifera. International Journal of Applied Science and Technology, 2, 314-322.
 Kehinde, O. O., Oluwatoyin, T. A., & Aderonke, O. O. (2009). Comparative analysis of the efficiencies of two low cost adsorbents in the removal of Cr(VI) and Ni(II) from aqueous solution. African Journal of Environmental Science and Technology, 3, 360-369.
 Omar, W., & Al-Itawi, H. (2007). Removal of Pb2+ ions from aquoues solutions by adsorption on kaolinite clay. American Journal of Applied Sciences, 4, 502-507. http://dx.doi.org/10.3844/ajassp.2007.502.507
 Rafika, S., Djilali, T., Benchreit, B., & Ali, B. (2009). Adsorption of heavy metals (Cd, Zn and Pb) from water using keratin powder prepared from algerien sheep hoofs. European Journal of Scientific Research, 35, 416-425.
 Shukla, A., Zhang, Y., Dubey, P., Margrave, J. L., & Shukla, S. S. (2002). The role of sawdust in the removal of unwanted materials from water. Journal of Harzadous Materials, B95, 137-152. http://dx.doi.org/10.1016/S0304-3894(02)00089-4
 Sun, G., & Shi, W. (1998). Sunflower stalks as adsorbents for the removal of metal ions from wastewater. Industrial and Engineering Chemistry Research, 37, 1324-1328. http://dx.doi.org/10.1021/ie970468j
 Todorovi, Z., Pol, P., Dgordjevi, D., & Autoni, J. S. (2001). Lead distribution in water and its association with sediments constituents of the Baije Lake. Journal of the Serbian Chemical Society, 66, 697- 708.
 Wan Ngah, W. S., & Hanafiah, M. A. K. M. (2008). Removal of heavy metal ions from wastewater by chemically Modified plant wastes as adsorbents: A review. Bioresource Technology, 99, 3935-3948. http://dx.doi.org/10.1016/j.biortech.2007.06.011
 Zhou, X., Xue, X., & Xue, X. (2011). Study on adsorption of heavy metal ion in metallurgical wastewater by sepiolite. Proceedings of the 2nd International Conference on Environmental Science and Development, Singapore, 100-103.