The problem of the existence of theorethical entities . Scientiae Studia, [S. l.], v. 3, n. 2, p. 277–312, 2005. DOI: 10.1590/S1678-31662005000200008. Disponível em: https://revistas.usp.br/ss/article/view/11038.. Acesso em: 19 may. 2024.