i'm not sure if everyone knows this, but Google, in cooporation w/ many amazing libraries, has started to digitize old books for all of us to view...and if they are not copywrited, you can download them. i've been doing so mostly for old architecture treatises, but i've also gotten some one oriental rugs. so the history person might enjoy this and so i thought i would share...i've attached a link. enjoy.
http://books.google.com/...ental+rugs&as_brr=1
here's an example of a listing which you can fully download the text as a .pdf file...
How to Know Oriental Rugs, a Handbook
by Mary Beach Langton - Rugs, Oriental - 1920 - 244 pages
...actually, the more i think a/ what google is doing, i think it's amazing... not all of us can make it up to harvard to research books written at the turn of last century...