Authors
Kamen Petrov
UNWE, Faculty of Management and Administration, Department of Regional Development, Sofia, Bulgaria
Mihaela Georgieva-Petrova
Konstantin Preslavski University of Shumen, Faculty of Natural Sciences, Department of Geography, Regional Development and Tourism, Shumen, Bulgaria
Milena Stoyanova
Konstantin Preslavski University of Shumen, Faculty of Natural Sciences, Department of Geography, Regional Development and Tourism, Shumen, Bulgaria