LUUKKAINEN, J. Approximating continous maps of metric spaces into manifolds by embeddings. MATHEMATICA SCANDINAVICA, [S. l.], v. 49, p. 61–85, 1981. DOI: 10.7146/math.scand.a-11921. Disponível em: https://www.mscand.dk/article/view/11921. Acesso em: 8 may. 2024.