WANJALA, V.; OBIERO , B. A. ON CLASS (BD) OPERATORS OF ORDER (n+k). International Research Journal of Rongo University, [S. l.], v. 3, n. 1, p. 22–27, 2025. Disponível em: http://journals.rongovarsity.ac.ke/index.php/IJORU/article/view/85. Acesso em: 3 aug. 2025.