FROMM, Viktor. Morse homotopy and topological conformal field theory. Topological Methods in Nonlinear Analysis, [S. l.], v. 45, n. 1, p. 7–36, 2015. DOI: 10.12775/TMNA.2015.001. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2015.001. Acesso em: 1 jul. 2025.