1981 Sc 5138-5141 River Fleet of the USSR Scott 4957-4960

1981. River Fleet of the USSR.
Catalog numbers: Scott 4957-4960, Standard Collection 5138-5141, Michel 5088-5091, Yvert 4823-4826.
Condition: MNHOG.
Issued on: July 9, 1981.
Perforation: comb 12½ x 12.
Printing: Offset lithography.
Size: 30 x 42 mm.
Colors: Multicolor.
Face value: 4 Russian kopek; 6 Russian kopek; 15 Russian kopek; 32 Russian kopek.
Quantity: 6,400,000; 5,800,000; 4,300,000; 4,100,000.