Hearings Relating to H.R. 15626, H.R. 15649, H.R. 16613, H.R. 16757, H.R. 15018, H.R. 15092, H.R. 15229, H.R. 15272, H.R. 15336, and H.R. 15828, Amending the Subversive Activities Control Act of 1950: Hearings Before the Committee on Un-American Activities, House of Representatives, Ninetieth Congress, Second Session