SALAMAH, Soha Ali. The Sub- Laplacian on The Heisenberg Group and Itʼs Spectral Properties. Arab Journal for Sciences and Research Publishing, New Mexico, United States, v. 6, n. 1, p. 105–97, 2020. DOI: 10.26389/AJSRP.S181019. Disponível em: https://journals.ajsrp.com/index.php/ajsrp/article/view/2239. Acesso em: 24 jan. 2026.