Gebreyesus, Sofani Tafesse. “Heavy Metals in Contaminated Soil: Sources & Washing through Chemical Extractants”. American Scientific Research Journal for Engineering, Technology, and Sciences 10, no. 1 (September 21, 2014): 54–60. Accessed April 25, 2024. https://www.asrjetsjournal.org/index.php/American_Scientific_Journal/article/view/730.