V. REVATHI; P. MAHESWARI NAIK. On Quasi-class (Q) Operator. International Journal of Mathematics And its Applications, [S. l.], v. 7, n. 4, p. 31–35, 2019. Disponível em: http://ijmaa.in/index.php/ijmaa/article/view/202. Acesso em: 3 may. 2024.