1. Afanas’eva, E.S., Ryazanov, V.I., Salimov, R.R.: On mappings in Orlicz–Sobolev classes on Riemannian manifolds. Ukr. Mat. Visn. 8(3), 319–342, 461 (2011) (in Russian). (transl. in J. Math. Sci. (N. Y.) (2012). 181(1), 1–17)
2. Beardon, A.F.: The geometry of discrete groups. Graduate Texts in Math, vol. 91. Springer-Verlag, New York (1983)
3. Bourbaki, N.: General topology. The main structures. Nauka, Moscow (1968). (in Russian)
4. Federer, H.: Geometric measure theory. Die Grundlehren der mathematischen Wissenschaften, vol. 153. Springer-Verlag, New York (1969)
5. Forster, O.: Riemannsche Flächen, Heidelberger Taschenbücher, vol. 184. Springer-Verlag, Berlin-New York (1977)