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 (Oct. 2010), 135–137. DOI:https://doi.org/10.54055/ejtr.v3i2.57.