C. B. N. Bert-Okonkwor, K. C. Okolie, F. O. Ezeokoli, and G. C. Ohazulume. “Comparative Analysis of Concrete Strength Made from Selected Brands of Cement in Anambra State, Nigeria”. Archives of Current Research International, vol. 19, no. 4, Jan. 2020, pp. 1–10, doi:10.9734/acri/2019/v19i430162.