Chengula, D. D. H., P. J. J. Msambichaka, and P. B. Middendorf. “Synthetic Determination of Specific Density, Specific Surface Area and Particle Size Distribution of Cementitious Powder Materials”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 41, no. 2, Sept. 2018, pp. 177-89, https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/9303.