 The Office of Strategic Services (OSS) took the lead in recruiting and organizing secret expeditions to Europe, often acquiring rare materials from bookshops just before the Gestapo arrived.Massive amounts of books, magazines and documents were collected-- too much to transport-- so the new technique of micro photography was developed successfully.After the D-Day landings in 1944, librarians became part of information search teams under Army command, searching especially for current intelligence, as well as patents and technical manuals.