BONDARENKO, V. G. Estimates of the heat kernel on a manifold of nonpositive curvature. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 50, n. 8, p. 1129–1136, 1998. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4862. Acesso em: 14 apr. 2025.