1977 Sc 4638. World Electronics Congress. Scott 4561

1977. World Electronics Congress.
Catalogs: Scott 4561, Standard Collection 4638, Michel 4588, Yt 4362.
Issued on: 1977-04-06.
Perforation: comb 11½
Printing: Photogravure
Size: 40 x 28 mm
Colors: Blue, red, gray
Face value: 6 Russian kopek
Print run: 3,600,000