1972 Sc 4052 International Book Year Scott 3967

1972. International Book Year.
Catalogs: Scott 3967, Standard Collection 4052, Mi 4002, Yt 3831.
Condition: MNHOG.
Issued on: May 5, 1972.
Perforation: comb 11½.
Printing: Photogravure.
Size: 40 x 28 mm.
Colors: Multicolor.
Face value: 6 Russian kopek.
Quantity: 2,500,000.