sentences:  These stamps are known both perforated and imperforate and the 40,000 Rs and 75,000 Rs stamps were also surcharged with an overprint 700,000 Rs.From 1924, upon a decree from the central government of the USSR, only regular Soviet Union issued stamps were in use until November 1991.During this period several stamps with Armenian nationalistic and ethnic topics were issued by the central government, such as a 1950 set of three stamps to commemorate the 30th anniversary of the founding of the Soviet Armenian Republic, views of Erevan with Mount Ararat in 1960, and Armenian national costumes in 1961 and notable Armenian personalities.