On the existence of periodic solutions under the light of semi-Fredholm operators for some evolution equations. Gulf Journal of Mathematics, [S. l.], v. 19, n. 1, p. 190–207, 2025. DOI: 10.56947/gjom.v19i1.2531. Disponível em: https://www.gjom.org/index.php/gjom/article/view/2531. Acesso em: 20 aug. 2026.