by KHRISTOV,STOJAN N, TODOROV,JJORDAN K, MANUELJAN,KHARUTJUN S
Year of Publication 15.10.1987

by GENCHEVA,DELKA T, MINKOV,ILIJA I, TODOROV,JJORDAN K
Year of Publication 16.09.1985

by ELENKOV,ELENKO S, KOVACHEV,ATANAS N, KHRISTOV,STOJAN N, TODOROV,JJORDAN K, MANUELJAN,KHARUTJUN S
Year of Publication 14.02.1986

by KHRISTOV,STOJAN N, TODOROV,JJORDAN K, MANUELJAN,KHARUTJUN S, GENCHEV,SPAS G
Year of Publication 16.09.1985

by IVANOV,LJUBEN S, TODOROV,JJORDAN K, IVANOVA,MARIJA N
Year of Publication 15.04.1982