FUGLEDE, B. A sharpening of a theorem of Bouligand. With an application to harmonic maps. Annales Fennici Mathematici, [S. l.], v. 31, n. 1, p. 173–190, 2006. Disponível em: https://afm.journal.fi/article/view/135155. Acesso em: 25 nov. 2024.