by ENCHEVA,MILKA A, DOBREVA,EKATERINA D, GAVRILOVA,MARIANA L, TRANDAFILOV, ARKADIJJ T
Year of Publication 15.12.1982

by TRANDAFILOV,ARKADIJJ T, DOBREVA,EKATERINA D, ENCHEVA,MILKA A, LIRKOV,ALEKSANDR L, PETROV,KHRISTO B, PINDEVA,LILIJA I
Year of Publication 14.11.1986

by FAKIROV,STOJJKO KH.,BG, EVSTATIEV,GEORGI P.,BG, TRANDAFILOV,ARKADIJJ T.,BG, PETROVA,SLAVA G.,BG
Year of Publication 15.12.1988

by TRANDAFILOV,ARKADIJJ T, ENCHEVA,MILKA A, GAVRILOVA,MARIANA L, PETROV, KHRISTO B
Year of Publication 15.10.1982