Lines of axial curvature at critical points on surfaces mapped into R4. São Paulo Journal of Mathematical Sciences, [S. l.], v. 6, n. 2, p. 277–300, 2012. DOI: 10.11606/issn.2316-9028.v6i2p277-300. Disponível em: https://www.revistas.usp.br/spjournal/article/view/74476.. Acesso em: 3 maio. 2024.