Anonymous - Affiches soviétiques de propagande - 1970s

I am selling three propaganda posters (!) of a historical nature from the former USSR. They date from 1976 (see photo) and were purchased on site during a trip.
The dimensions are 57x87cm. The condition is good although the paper has slightly yellowed; there is a somewhat marked horizontal fold on the top of the 1928-1945 poster; on the 1948-1968 poster, there is a tear at the bottom and a slight vertical brown line at the top; these details are visible in the photos.
The three posters are sold together; it is not possible to buy them separately.