1. Smirnov S.V., Akad. publ., 2, 57 (2020)
2. Torres V.R.M., Lorenzo A.S., Castro S. J. et al., J. of sc. and techn. pol. man., 4(10), 905 (2019)
3. Werner K., Griese K.M., Bosse S., J. of sust. able tour., 0021 (2020)
4. Secret. of State for Tour. of France and World Tour. Organ. (WTO), 802 (2001)
5. Vikulova O.N., ModernLib.ru