CAPONETTI, Diana; TROMBETTA, Alessandro; TROMBETTA, Giulio. Optimal retraction problem for proper $k$-ball-contractive mappings in $C^m [0,1]$. Topological Methods in Nonlinear Analysis, [S. l.], v. 53, n. 1, p. 111–125, 2019. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2018.041. Acesso em: 3 jul. 2025.