Uosif, M. ., & Mostafa, A. . (2020). Assessment of Natural Radioactivity Levels in Soil and Chemical Fertilizers Widely used in Upper Egypt: Natural Radioactivity in Soil and Chemical Fertilizers. WAS Science Nature (WASSN) ISSN: 2766-7715, 3(1), 1–7. Retrieved from http://worldascience.com/journals/index.php/wassn/article/view/10