Mohamed, Y. T., L. S. Hussin, H. H. Gad, A. M. Daifullah, and S. A. Abo-El-Enein. “Membrane Stabilitiy and Removal of Cobalt from Waste Solution Using Liquid Emulsion Membrane”. Journal of Membrane and Separation Technology, vol. 2, no. 1, Feb. 2013, pp. 102-8, doi:10.6000/1929-6037.2013.02.01.10.