Kimaiyo , P. J., J. Mutiso, and M. Kosgei. “ Construction of a Five-Level V-Dimensional Modified Third Order Rotatable Designs Using a Pair of Pairwise Balanced Designs ”. African Journal of Education,Science and Technology (AJEST) 5, no. 3 (December 23, 2019): Pg 179 – 189. Accessed April 3, 2026. https://ajest.org/index.php/ajest/article/view/758.