Mohd Ali, Ahmad Zurisman, et al. “The Effect of Dry Mix Sodium Hydroxide onto Workability and Compressive Strength of Geopolymer Paste”. International Journal of Integrated Engineering, vol. 12, no. 9, Dec. 2020, pp. 114-20, https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/6407.