by BARBUTOV,VENELIN G.,BG, TURLAKOV,KHRISTO A.,BG, MACHEV,STEFAN S.,BG
Year of Publication 15.02.1989

by BARBUTOV,VENELIN G.,BG, TURLAKOV,KHRISTO A.,BG, MACHEV,STEFAN S.,BG
Year of Publication 15.12.1988

by BARBUTOV,VENELIN G.,BG, TURLAKOV,KHRISTO A.,BG, BORSHUKOV,DOBRIN G.,BG, KHRISTOVA,IRENA G.,BG, KOKALICHEV,NIKOLAJJ K.,BG
Year of Publication 15.03.1989