THE CONTROLLABLE PITCH PROPELLER
Dayton, OH: Materiel Division U. S. Army Air Corps, 1941. Paperback. 33 pp; staple bound booklet, translated from French magazine L'Aerophile; (Translation No. 347) highly technical details; typewritten pages, recto only, printed on "blueprint" paper; has name of former owner writen in top right corner on front cover, published in.....