Interkosmos , the collaboration of communist countries in various phases of space research.
Designer : Jaroslav Lukavsky
Engravers : Bedrich Housa
(20h, 1K & 1,60) Milos Ondracek
( 40h,60h & both 1,20K)
Printing Process : Combination , 1 colour (black) engraved & multicolour photogravure
Scott 1716 – 1721. Scott 1720A was issued in 1971.For Scott 1722 – 1725 see page 3