ANDRES, Jan; KRAJC, Bohumil. Unified approach to bounded, periodic and almost periodic solutions of differential systems. Annales Mathematicae Silesianae, [S. l.], v. 11, p. 39–53, 1997. Disponível em: https://journals.us.edu.pl/index.php/AMSIL/article/view/14183. Acesso em: 15 apr. 2025.