Mohamad, S., & Radzi Abas, M. (2005). Enrichment of Cu, Zn and Cd by Solid-Phase Extraction using Silica Gel Chemically Modified with Hydroxamic Acid Prior to Their Determination by Flame Atomic Absorption Spectrometry. Malaysian Journal of Science, 24(2), 65–70. Retrieved from https://juku.um.edu.my/index.php/MJS/article/view/8330