Ibrahim, A., E. A. Nwaibeh, M. O. Francis, and C. J. Okigbo. “On Collapse Of Order-Preserving and Idempotent of Order-Preserving Full Contraction Transformation Semigroup”. International Journal of Mathematical Sciences and Optimization: Theory and Applications 10, no. 2 (April 14, 2024): 1 - 8. Accessed November 22, 2024. http://ijmso.unilag.edu.ng/article/view/2076.