A Fourth-Order Derivative-Free Operator Marching Method for Helmholtz Equation in Waveguides. Journal of Computational Mathematics, [S. l.], v. 25, n. 6, p. 719–729, 2021. Disponível em: https://staging.gsp.tricubic.dev/JCM/article/view/11861. Acesso em: 18 mar. 2026.