I'm convinced that all the pre-war books in Doc Mitchell's house are a joke on players who played Fallout 3. They'll see all those pre-war books laying around and go into fits thinking "oooh, free money, must collect them all! nom nom nom". (Only for them to find out later that they aren't special and aren't used for anything. At which point the Obsidian dev who put them there is probably quietly snickering.) Its not just the books that are a joke. Its the entire salvage system. There doesn't appear to be any recipes for makeshift weaponry like Railguns, Nuka-Cola Grenades or whathaveyou in Fallout New Vegas. At about halfway through the game I stopped bothering to collect scrap metal, scrap electronics, wonderglue, duct tape, vacuum cleaners etc because there's almost nothing you can do with them. :(