by VELEVA,MARIANA N, VASILEV,ILIJA K, VCHEV,KOSTADIN D
Year of Publication 14.08.1987

by DONCHEV,STEFAN D, VCHEV,KOSTADIN D, KOLEVA,KIRILKA B
Year of Publication 15.01.1986

by KOLEV,BISER G, JAKIMOV,TIKHOMIR N, DONCHEV,STEFAN D, KOLEV,NIKOLA T, BOJJKOVA,KHRISTINA N, GEORGIEV,PETR A, BATEV,KRSTIN P, VCHEV,KOSTADIN D
Year of Publication 15.11.1984

by KOLEV,BISER G, JAKIMOV,TIKHOMIR N, DONCHEV,STEFAN D, KOLEV,NIKOLA T, BOJJKOVA,KHRISTINA N, GEORGIEV,PETR A, VCHEV,KOSTADIN D, BATEV,KRSTIN P
Year of Publication 15.10.1984

by IVANOV,VASIL I, VCHEV,KOSTADIN D, NESHKOV,LJUBOMIR I
Year of Publication 15.10.1981

by FILIPOV,FILIP I, BATEV,KRSTIN P, VCHEV,KOSTADIN D
Year of Publication 12.12.1980

by VCHEV,KOSTADIN D, DZHUDZHEV,MARIN S, JALMOV,VLADISLAV S, NESHKOV,LJUBOMIR N
Year of Publication 15.05.1981

by BATEV,KR'STIN P.,BG, V'CHEV,KOSTADIN D.,BG, KHADZHIEVA,VIRDZHINIJA K.,BG, KOLEV,BISER G.,BG
Year of Publication 14.10.1988

by ZAKHARIEVA,MASHENKA D.,BG, BATEV,KR'STIN P.,BG, DISHKOV,PET'R S.,BG, VASILEV,ILIJA K.,BG, V'CHEV,KOSTADIN D.,BG, CHOLAKOV,NIKOLA I.,BG
Year of Publication 15.09.1988