Kok, Johan, and Saptarshi Bej. “Coloring Sums of Extensions of Certain Graphs”. Journal of Algebra Combinatorics Discrete Structures and Applications 5, no. 1 (January 15, 2018): 19–27. Accessed September 13, 2026. https://jacodesmath.com/index.php/jacodesmath/article/view/80.