Georgina Lukanova, Georgina Lukanova. “Improving Service Effectiveness in the High-Class Hotels in Varna (Bulgaria): Supervisor: Assoc. Prof. Tanya Dabeva, PhD Institution Awarding the Ph. D. Degree: University of Economics-Varna, Bulgaria Th Date of Defence: 19 October 2012”. European Journal of Tourism Research 6, no. 1 (March 1, 2013): 88–91. Accessed October 20, 2021. https://ejtr.vumk.eu/index.php/about/article/view/123.