@book{mayer_zbaraszewski_pieńkowski_gach_gernert_2019, 
  title={Cross-Border Tourism in Protected Areas}, 
  DOI={10.1007/978-3-030-05961-3}, 
  publisher={Springer International Publishing}, 
  author={Mayer and Zbaraszewski and Pieńkowski and Gach and Gernert}, 
  year={2019}
  }