Generalized Inner Structure Spaces: Indefinite Sesquilinear Forms in Fréchet Spaces and Their Applications. European Journal of Pure and Applied Mathematics, Maryland, USA, v. 19, n. 1, p. 6727, 2026. DOI: 10.29020/nybg.ejpam.v19i1.6727. Disponível em: https://www.ejpam.com/index.php/ejpam/article/view/6727. Acesso em: 17 feb. 2026.