K. Arap Tonui, M., W. Mwangi, I. and Wanjau, R. 2019. Recovery of Zn2+, Fe2+ and Mn2+ from Some Selected Edible Vegetables and Pumpkin using Modified Maize Cobs. American Scientific Research Journal for Engineering, Technology, and Sciences. 51, 1 (Jan. 2019), 86–102.