"USSR - CIRCA 1971: A stamp printed in USSR shows image of a Benois Madonna by Leonardo with the inscription "USSR. Leonardo. Benois Madonna", series, circa 1971
"USSR - CIRCA 1973: A stamp printed in USSR shows image of a Lady in the garden by Monet with the inscription "USSR. Monet. Lady in the garden. 1867.", series
"USSR - CIRCA 1973: A stamp printed in USSR shows image of a Stilllife with dead gamebird and lobster by Snyders with the inscription "USSR. Snyders. Stilllife with dead gamebird and lobster", series, circa 1973