Ambrose, E. E. ., F. O. . Okafor, and M. E. . Onyia. “Scheffe’s models for optimization of tensile and flexural strength of recycled ceramic tile aggregate concrete”. Engineering and Applied Science Research, vol. 48, no. 5, July 2021, pp. 497-08, https://ph01.tci-thaijo.org/index.php/easr/article/view/243166.