BRATUSZEWSKA, E. Initial boundary value problem for a mechanical system with local stroke change of stiffness. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 5, p. 5–12, 2006. Disponível em: https://studmath.uken.krakow.pl/article/view/13288. Acesso em: 31 oct. 2026.