, . . English summaries. Butlletí de la Societat Catalana de Matemàtiques, [S. l.], v. 25, n. 1, p. 101–103, 2010. Disponível em: https://revistes.iec.cat/index.php/BSCM/article/view/62453.001. Acesso em: 9 may. 2024.