MRCUN, J.; SEMRL, P. Multiplicative bijections between algebras of differentiable functions. Annales Fennici Mathematici, [S. l.], v. 32, n. 2, p. 471–480, 2007. Disponível em: https://afm.journal.fi/article/view/135205. Acesso em: 26 apr. 2025.