HOSSEINZADEH, H.; SHAHGHOLIAN, H. Qualitative aspects of a free boundary problem. Annales Fennici Mathematici, [S. l.], v. 24, n. 1, p. 109–121, 1999. Disponível em: https://afm.journal.fi/article/view/134943. Acesso em: 25 nov. 2024.