Voroshilov K.E., Lessons of war with Finland, Unpublished report of Narkom for Defence of USSR K.E. VOroshilov at the plenum of ZK VKP(b), 28 March 1940, (Russian) [1]
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"70 років мужності і звитяги" [70 Years of Courage and Victory] (PDF). Viisko Ukrainy (in Ukrainian). May 2011. p. 30. Retrieved 15 April 2020.