A. Elzain, A., K. Sarn, A., M. Mukhtar, O., & A. Abbasher, M.
(2009).
Measurements of Radon gas Concentration in a Soil at Some Towns in Kassala State.
Gezira Journal Of Engineering And Applied Sciences, 4(1), 15 - 42.
Retrieved from http://37.60.236.48/index.php/gjeas/article/view/2077