BRUDNYI, A. .; BRUDNYI, Y. . Extension of Lipschitz Functions Defined on Metric Subspaces of Homogeneous Type. Revista Matemática Complutense, v. 19, n. 2, p. 347–359, 13 jul.2006 https://doi.org/10.5209/rev_REMA.2006.v19.n2.16596.