Authors
Svetla Stankova
„Konstantin Preslavski” University of Shumen, Faculty of Natural Sciences, Department of Geography and Regional Development, Shumen
Tzanko Tzankov
South-West University „Neofit Rilski” – Blagoevgrad, Faculty of Mathematics and Natural Sciences, Department of Geography, Ecology and Environment Protection, Blagoevgrad
Rosen Iliev
South-West University „Neofit Rilski” – Blagoevgrad, Faculty of Mathematics and Natural Sciences, Department of Geography, Ecology and Environment Protection, Blagoevgrad