VAN DEN BERG, M.; DESJARDINS, S.; GILKEY, P. B. Functorality and heat content asymptotics for operators of Laplace type. Topological Methods in Nonlinear Analysis, [S. l.], v. 2, n. 1, p. 147–162, 1993. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1993.035. Acesso em: 29 mar. 2024.