VASILIEV , A. Yu. Quasi-variance of the modulus of homotopical classes of curves and Teichmuller’s problem. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 43, n. 3, p. 329–336, 1991. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/9611. Acesso em: 12 jan. 2026.