HASSANNEZHAD, A.; KOKAREV, G. Sub-Laplacian eigenvalue bounds on sub-Riemannian manifolds. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE, [S. l.], v. 16, n. 4, p. 1049-1092, 2016. DOI: 10.2422/2036-2145.201409_005. Disponível em: https://journals.sns.it/index.php/annaliscienze/article/view/474. Acesso em: 20 feb. 2026.