WEI, J.; ZHONG, X.; ZOU , W. On Sirakov’s open problem and related topics. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE, [S. l.], v. 23, n. 2, p. 959-992, 2022. DOI: 10.2422/2036-2145.202010_010. Disponível em: http://20.103.181.36/index.php/annaliscienze/article/view/5429. Acesso em: 26 may. 2025.