GILKEY, Peter B. Heat content asymptotics of non-minimal operators. Topological Methods in Nonlinear Analysis, [S. l.], v. 3, n. 1, p. 69–80, 1994. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1994.004. Acesso em: 8 jul. 2025.