1981 Sc 5106-5108 20th Anniversary of First Manned Space Flight Scott 4925-4927

1981. 20th Anniversary of First Manned Space Flight.
Catalog numbers: Scott 4925-4927, Standard Collection 5106-5108, Michel 5056Zf-5058Zf, Yvert 4793-4795.
Condition: MNHOG.
Issued on: April 12, 1981.
Perforation: comb 11½ x 12.
Printing: Photogravure.
Size: 52 x 55.5 mm.
Colors: Multicolor.
Face value: 6 Russian kopek; 15 Russian kopek; 32 Russian kopek.
Quantity: 6,000,000; 5,000,000; 4,000,000.