Existence and stability results of relaxation fractional differential equations with Hilfer--Katugampola fractional derivative. Advances in the Theory of Nonlinear Analysis and its Application, [S. l.], v. 4, n. 4, p. 299–315, 2023. Disponível em: https://atnaea.org/index.php/journal/article/view/138.. Acesso em: 10 may. 2026.