NYSTRÖM, Kaj. Regularity below the continuous threshold in a two-phase parabolic free boundary problem. MATHEMATICA SCANDINAVICA, [S. l.], v. 99, n. 2, p. 257–286, 2006. DOI: 10.7146/math.scand.a-15012. Disponível em: https://tidsskrift.dk/math/article/view/15012. Acesso em: 14 aug. 2026.