1990 Sc 6191-6193 Nobel Prize Winners Scott 5938-5940

1990. Nobel Prize Winners.
Catalogs: Scott 5938-5940, Standard Collection 6191-6193, Michel 6135-6137, Yt 5796-5798.
Issued on: October 22, 1990.
Perforation: comb 12¼.
Printing: Offset lithography.
Size: 28 x 40 mm.
Colors: Light brown; black; brown-gray.
Face value: 15 Russian kopek.