“It provides valuable insight into recent research conducted in the Southeastern European mountain regions. And thus it can be of interest to a diverse audience, including students, researchers and practitioners of different fields, e.g. in the fields of geography, ecology, environmental studies and tourism. … it reaches its goal of providing multiple pieces of evidence that sustainability principles should be used at every scale of geo-ecologic planning in mountain regions.” (Eszter Tanács, Hungarian Geographical Bulletin, Vol. 66 (1), 2017)