Biyana, M. . “Level of Selected Precedence Pollutants in Soils of the Industrial Regions of Welmera District (Oromiya Special Zone Around Finfinne), Ethiopia”. Journal of Science and Development, vol. 2, no. 2, July 2021, pp. 123-36, https://journals.hu.edu.et/hu-journals/index.php/agvs/article/view/71.