Soviet Union. Spet︠s︡ial 'nai︠a︡ komissii︠a︡ po ustanovlenii︠u︡ i rassledovanii︠u︡ obstoi︠a︡tel'stv rasstrela nemet︠s︡ko-fashistskimi zakhvatchikami v Katynskom lesu voennoplennykh pol'skikh ofit︠s︡erov