Kliment Naydenov. CIRCULAR TOURISM AS A KEY FOR ECO-INNOVATIONS IN CIRCULAR ECONOMY BASED ON SUSTAINABLE DEVELOPMENT. SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 18th International Multidisciplinary Scientific GeoConference SGEM2018, Ecology, Economics, Education and Legislation, 2018, pp. 135-142. https://doi.org/10.5593/sgem2018/5.3/s28.017