"Study of Radon Concentrations in Some of public Ground water wells, Sana’a - Yemen". (2023) Hadhramout University Journal of Natural & Applied Sciences, 20(1). موجود في: https://hu.edu.ye/hu-publications/journals/index.php/hujnas/article/view/149 (تاريخ الوصول: 25 يوليو 2026).