From Department of the Army, Frankford Arsenal, Silencers - Principles and Evaluations . Published in 1968, it is 208 pages in length,softcover, and 5.5"x8.5" in size. Contains: Description and Evaluations of Silencers for many, many firearms including High Standard, M1903, M1 Carbine, Sten, Walther, M3 .45 Cal. and more. Silencer theory and principles are explained as well as accompanied by lots of pictures and technical drawings. For entertainment use only!