Braun, Francisco, Luis Renato Gonçalves Dias, and Jean Venato Santos. “On Global Invertibility of Semi-Algebraic Local Diffeomorphisms”. Topological Methods in Nonlinear Analysis 58, no. 2 (December 2, 2021): 713–730. Accessed July 22, 2024. https://apcz.umk.pl/TMNA/article/view/36352.