2015, International trends in recreational and wellness tourism 2. Februar 2020 Éva Csirmaz, Károly Peto Procedia Economics and Finance 32:755-762 DOI:10.1016/S2212-5671(15)01458-6 https://www.researchgate.net/publication/289993050_International_Trends_in_Recreational_and_Wellness_Tourism