HAMEED HASSAN, T.; MOHAMMAD ABBAS, R. Prime Graceful Labeling. International Journal of Engineering and Technology, [S. l.], v. 7, n. 4.36, p. 750–752, 2018. DOI: 10.14419/ijet.v7i4.36.24234. Disponível em: https://sciencepubco.com/index.php/IJET/article/view/24234.. Acesso em: 14 mar. 2025.