H. . Kodama y P. W. . Michor, «The Homotopy Type of the Space of Degree 0 — Immersed Plane Curves», Rev. mat. complut., vol. 19, n.º 1, pp. 227–234, abr. 2006, doi: https://doi.org/10.5209/rev_REMA.2006.v19.n1.16660