1981 Sc 5102-5104 Soviet-Mongolian Space Flight Scott 4921-4923

1981. Soviet-Mongolian Space Flight.
Catalog numbers: Scott 4921-4923, Standard Collection 5102-5104, Michel 5052-5054, Yvert 4789-4791.
Condition: MNHOG.
Issued on: March 23, 1981.
Perforation: comb 12¼ x 12.
Printing: Offset lithography.
Size: 53 x 38 mm.
Colors: Multicolor.
Face value: 6 Russian kopek; 15 Russian kopek; 32 Russian kopek.
Quantity: 6,000,000; 4,800,000; 3,900,000.