BULGARIA: 10 Leva (1979) in silver (0,900) commemorating the Bulgarian-Soviet Cosmonaut Flight. National coat of arms above denomination and date on obverse. Cosmonaut flight space shuttle on reverse. Inside slab by NGC "PF 61 ULTRA CAMEO / JOINT SPACE FLIGHT / 23.85g". Cert number: 6635453-049. (KM 105a) & (Nikolov 134).