Felix Bitrus, Masok, et al. “X-Ray Shielding Characteristics of Sand Reenforced Plastic Concrete Blocks”.
EDUCATUM Journal of Science, Mathematics and Technology, vol. 12, no. 1, Feb. 2025, pp. 148-62,
https://ejournal.upsi.edu.my/index.php/EJSMT/article/view/11049.