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POLAND - JANUARY 01: Doctors Met In Committee, Supervised By Officers Of The Russian Army, Observing The Remains Of The Mass Grave At Katyn Near Smolensk In Poland When It Was Discovered. \ \ Shortly After The Soviet Invasion Of Poland September 17, 1940, Thousands O (Photo by Keystone-France/Gamma-Keystone via Getty Images)

POLAND - JANUARY 01:  Doctors Met In Committee, Supervised By Officers Of The Russian Army, Observing The Remains Of The Mass Grave At Katyn Near Smolensk In Poland When It Was Discovered. \ \ Shortly After The Soviet Invasion Of Poland September 17, 1940, Thousands O  (Photo by Keystone-France/Gamma-Keystone via Getty Images)