1977 SC 4698-4703 20th Anniversary of Space Exploration Scott 4589-4594

1977. 20th Anniversary of Space Exploration.
Catalog numbers: Scott 4589-4594, Standard Collection 4698-4703, Michel 4648-4653, Yvert 4404-4409.
Condition: MNHOG.
Issued on: October 4, 1977.
Perforation: comb 11½ x 12.
Printing: Photogravure.
Size: 26 x 55 mm.
Colors: Multicolor.
Face value: 3*10 Russian kopek; 3*20 Russian kopek.
Quantity: 7,800,000; 6,800,000; 6,800,000; 6,200,000; 5,300,000; 6,200,000.