M. Dimitrova, “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”, EJTR, vol. 3, no. 2, pp. 135–137, Oct. 2010.