N. N. S. MARZUKI, “An Investigation of Density and Thickness of Geopolymer Concrete as Gamma Ray Radiation Shielding Application”, EKST, vol. 3, no. 2, pp. 479–487, Dec. 2023, Accessed: May 13, 2024. [Online]. Available: https://publisher.uthm.edu.my/periodicals/index.php/ekst/article/view/10803