Harb, S., A. H. El-Kamel, A. M. Zahran, A. Abbady, and F. A. Ahmed. 2016. “Natural Radioactivity of Ground Water in Some Areas in Aden Governorate South of Yemen Region”. ANGLISTICUM. Journal of the Association-Institute for English Language and American Studies 3 (January). https://www.anglisticum.org.mk/index.php/IJLLIS/article/view/708.