V. PUNEETH; T. V. JOSEPH. On k-Near Perfect Numbers. International Journal of Mathematics And its Applications, [S. l.], v. 6, n. 2 - B, p. 61–65, 2018. Disponível em: https://ijmaa.in/index.php/ijmaa/article/view/701. Acesso em: 3 jul. 2024.