M.J.B, A., A. A.S.M.A, R. M.M, A. MJ.B, R. M.S, B. B.K, and I. S. “Fly-Ash As Admixture in Manufacturing of Cement - A Case Study”. Malaysian Journal of Science, vol. 27, no. 1, Apr. 2008, pp. 1-6, https://samudera.um.edu.my/index.php/MJS/article/view/7888.