by Esipko E.A.[SU], Khadzhiev S.N.[SU], Prokof'ev V.P.[SU], Atanasov A.[BG], Agaronov V.A.[SU], Martynenko A.G.[SU], P"rvanev L.[BG], Khristov V.[BG]
Year of Publication 27.03.1996

by KHRISTOV,KOL'O V.,BG, SIMEONOV,SIMEON V.,BG, STANCHEV,VESELIN R.,BG, KOMAREV,NIKOLA I.,BG, V'LKANOV,NIKOLAJJ D.,BG
Year of Publication 15.11.1988

by CHOLAKOV,KOSTADIN S.,BG, KHRISTOV,KOL'O V.,BG, STANCHEV,VESELIN R.,BG, KOMAREV,NIKOLA I.,BG, PALACHOROV,GANCHO G.,BG
Year of Publication 15.11.1988

by DAVIDOV,ANGEL G.,BG, BAK'RDZHIEV,VALENTIN I.,BG, KHRISTOV,KHRISTO V.,BG, SPIRIDONOV,NIKOLAJJ K.,BG, SIMEONOV,IVAN F.,BG
Year of Publication 15.03.1988

by ZHEKOV,SVETOZAR K.,BG, DIMITROVA,FROSINKA P.,BG, ZHEKOV,KIRIL V.,BG, KHRISTOV,KOL'O V.,BG, SIMEONOV,SIMEON V.,BG, STANCHEV,VESELIN R.,BG
Year of Publication 15.02.1988

by PETKOV,PLAMEN V.,BG, KOPCHELIJJSKI,JJORDAN S.,BG, NEJJCHEV,SLAVEJJKO K.,BG, GISHIN,NIKOLAJJ I.,BG, PEEV,RUMEN M.,BG, KHRISTOV,RADOSLAV V.,BG, MLADENOVA,DIANA KH.,BG
Year of Publication 14.10.1988

by ZHEKOV,KIRIL V.,BG, KHRISTOV,KOL'O V.,BG, NESHEV,KIRIL D.,BG, KHRISTOV,KHRISTO A.,BG, CONEV,JJORDAN C.,BG, STOJANOV,STOJAN N.,BG, TOPALOVA,DIANA I.,BG
Year of Publication 15.06.1988

by NEJJCHEV,SLAVEJJKO K.,BG, KHRISTOV,RADOSLAV V.,BG
Year of Publication 15.09.1980