Ziryanov, Aleksander I., Andriej Y. Korolev, Swietlana E. Mishlavtceva, and Azat A. Safarian. 2016. “Approaches to Active Tourism in the Urals and in Perm Krai”. Turyzm/Tourism 26 (1):79-84. https://doi.org/10.1515/tour-2016-0007.