K. Arap Tonui, M., I. W. Mwangi, and R. Wanjau. “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, vol. 51, no. 1, Jan. 2019, pp. 86-102, https://asrjetsjournal.org/index.php/American_Scientific_Journal/article/view/4602.