BULGARIA: 20 Leva (1979) in silver (0,900) commemorating the Centennial of Sofia as Capital. National coat of arms above ribbon on obverse. Personification head of Sofia or Bulgaria crowned with city walls on reverse. Inside slab by NGC "PF 63 ULTRA CAMEO / SOFIA AS NATIONS CAPITAL". Cert number: 6634253-024. (KM 106a) & (Nikolov 132).