KAZARIAN, M. È. The Chern-Euler number of circle bundle via singularity theory. MATHEMATICA SCANDINAVICA, [S. l.], v. 82, n. 2, p. 207–236, 1998. DOI: 10.7146/math.scand.a-13834. Disponível em: https://www.mscand.dk/article/view/13834. Acesso em: 28 apr. 2024.