Gitimoni Deka and  Krishna G Bhattacharyya,  Enrichment of Cr, Mn, Ni and Zn in Surface Soil.   journal   = {International Journal of Chemical and Molecular Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2009, vol. 27(3). 154 - 156
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/13560.