[no place of publication stated]: [no publisher stated] [no date noted] + April 9, 1953. Throbac I: [1]-5 pages. Throbac - Circuit Operation: [1]-7 pages + 1 plate leaf. 10 7/8 x 8 3/8 inches. Both are typescript carbons on thin paper, printed recto only. Paper clipped upper left. Includes..... More