Dimitrova, M. (2010) “Opportunities for improving congress tourismʼs competitiveness: Supervisor: Prof. Tichomir Pelov, Ph.D, University of National and World Economy, Sofia, Bulgaria Institution awarding the Ph. D. Degree: University of National and World Economy, Sofia, Bulgaria Date of defence: 25 th March 2010”, European Journal of Tourism Research, 3(2), pp. 135–137. doi: 10.54055/ejtr.v3i2.57.