KOCK, Joachim. Characteristic numbers of rational curves with cusp or prescribed triple contact. Mathematica Scandinavica, Berkeley, CA, United States, v. 92, n. 2, p. 223–245, 2003. DOI: 10.7146/math.scand.a-14402. Disponível em: https://journals.msp.org/mscand/article/view/817. Acesso em: 24 jul. 2026.