Solvability and Stability for Singular Fractional $(p, q)$-Difference Equation. Journal of Nonlinear Modeling and Analysis, [S. l.], v. 3, n. 4, p. 647–661, 2024. DOI: 10.12150/jnma.2021.647. Disponível em: https://global-sci.com/index.php/jnma/article/view/13621. Acesso em: 6 dec. 2025.