Shrestha, B., P. L. Homagai, M. R. Pokhrel, and K. N. Ghimire. “Removal of Copper (II) and Zinc (II) Ions from Aqueous Solution by Biosorption onto Aminated Tea Waste”. Journal of Nepal Chemical Society, vol. 28, May 2013, pp. 48-53, doi:10.3126/jncs.v28i0.8058.