1971 SC 3937-3939 50 years to the Soviet Autonomous Socialist Republics Scott 3816-3818

1971. 50 years to the Soviet Autonomous Socialist Republics.
Catalogs: Scott 3816-3818, Standard Collection 3937-3939, Mi 3888, 3918-3919, Yt 3604B, 3752-3753.
Condition: MNHOG.
Issued on: June 16-August 17, 1971.
Perforation: comb 12 x 12½.
Printing: Recess.
Size: 37 x 52 mm.
Colors: Dull red; medium blue; dark blue green.
Face value: 3*4 Russian kopek.
Quantity: 3,500,000; 4,600,000; 4,000,000.