, . . English summaries. Butlletí de la Societat Catalana de Matemàtiques, [S. l.], v. 25, n. 2, p. 211–212, 2011. Disponível em: https://revistes.iec.cat/index.php/BSCM/article/view/63831.001. Acesso em: 22 dec. 2024.