Al-Zahrani J, El-Taher A. Natural Radioactivity levels and Elemental Analysis of Cement by Gamma-Ray Spectrometer and Neutron Activation Analysis. ASRJETS-Journal. 2017;30(1):173-183. Accessed September 12, 2025. https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/2807