ABDUL HALIM, WANN SHARFRINA, and ABD SUKOR SARIF. “Potential Use of Coal Bottom Ash As Fine Aggregate Replacement: A Review”. Progress in Engineering Application and Technology, vol. 2, no. 2, Dec. 2021, pp. 018-24, https://publisher.uthm.edu.my/periodicals/index.php/peat/article/view/730.