ANDRES, Jan. Concluding remarks to problem of Moser and conjecture of Mawhin. Annales Mathematicae Silesianae, [S. l.], v. 10, p. 57–65, 1996. Disponível em: https://journals.us.edu.pl/index.php/AMSIL/article/view/14192. Acesso em: 8 apr. 2025.