by AROJO, DZHEKI S, DENKOV, ASEN K, CHERNEV, VASIL P, RASHEV, JORDAN J
Year of Publication 14.12.1990

by MANOLOV,VIKTOR E, CHERNEV,VASIL P, TODOROV,JJORDAN M, RASHEV,JJORDAN JJ, BENKOV,BORIS I, AROJJO,DZHEKI S, RADNEV,JANKO S
Year of Publication 16.06.1986

by RADENKOV,FILIP D, GINDEV,ANDREJJ V, MANOLOV,VIKTOR E, KOSTOV,KOSTADIN A, CHERNEV,VASIL P, AROJJO,DZHEKI S, IVANOV,ILIJA D
Year of Publication 15.05.1986