E. . C, A. . Imam, M. Balarabe, and O. O. O , Trans., “Graph-Theoretic Characterizations of Quasi-Idempotents in Full Order-Preserving Transformation Semigroup”, Babylonian Journal of Mathematics, vol. 2025, pp. 88–91, May 2025, doi: 10.58496/BJM/2025/009.