PONRAJ, R.; PARTHIPAN, J. X. V.; KALA, R. A Note on Pair Sum Graphs. Journal of Scientific Research, [S. l.], v. 3, n. 2, p. 321–329, 2011. DOI: 10.3329/jsr.v3i2.6290. Disponível em: https://banglajol.info/index.php/JSR/article/view/6290. Acesso em: 18 may. 2022.