MP4 : Prof. Dimitar Dimitrov - University of National and World Economy, BulgariaFLV : Prof. Dimitar Dimitrov - University of National and World Economy, BulgariaMP4 FOR IPOD (edge) : Prof. Dimitar Dimitrov - University of National and World Economy, BulgariaMP3 : Prof. Dimitar Dimitrov - University of National and World Economy, Bulgaria