TCHERNOV, Vladimir. Homotopy Groups of the Space of Curves on a Surface. Mathematica Scandinavica, Berkeley, CA, United States, v. 86, n. 1, p. 36–44, 2000. DOI: 10.7146/math.scand.a-14280. Disponível em: https://journals.msp.org/mscand/article/view/925. Acesso em: 24 jul. 2026.