MAUGESTEN, P. A.; MOE, T. K. The $2$-Hessian and sextactic points on plane algebraic curves. MATHEMATICA SCANDINAVICA, [S. l.], v. 125, n. 1, p. 13–38, 2019. DOI: 10.7146/math.scand.a-114715. Disponível em: https://www.mscand.dk/article/view/114715. Acesso em: 28 mar. 2024.