Babarinsa, Olayiwola, and Hailiza Kamarulhaili. “Mixed Energy of a Mixed Hourglass Graph”. Communications in Mathematics and Applications 10, no. 1 (March 31, 2019): 45–53. Accessed August 18, 2025. https://www.journals.rgnpublications.com/index.php/cma/article/view/1143.