CINTI, Chiara. Sub-solutions and mean-value operators for ultraparabolic equations on Lie groups. Mathematica Scandinavica, Berkeley, CA, United States, v. 101, n. 1, p. 83–103, 2007. DOI: 10.7146/math.scand.a-15033. Disponível em: https://journals.msp.org/mscand/article/view/664. Acesso em: 24 jul. 2026.