1991 Sc 6227-6229 Defend the native nature Scott 5965-5967

1991. Defend the native nature.
Catalogs: Scott 5965-5967, Standard Collection 6227-6229, Michel 6169-6171, Yt 5830-5832.
Condition: MNHOG.
Issued on: February 5, 1991.
Perforation: comb 11½.
Printing: Photogravure.
Size: 40 x 28 mm.
Colors: Multicolor.
Face value: 10 Russian kopek; 15 Russian kopek; 20 Russian kopek.
Quantity: 3,000,000; 2,100,000; 2,100,000.