“Oblong Difference Mean Prime Labeling of Some Planar Graphs”, Int. J. Emerg. Trends Sci. Technol., vol. 4, no. 11, pp. 6344–6348, Nov. 2017, Accessed: Sep. 28, 2026. [Online]. Available: http://igmpublication.com/ijetst.in/index.php/ijetst/article/view/1196