Sources for Luger books are many, Amazon has them, while Simpsons has a good selection of gun books on the Luger and the link at
www.lugerforum.com on the left would take you to Simpsons and you can look at some nice Lugers for sale [img]smile.gif[/img]
Ray Riling has sent me the last two of Jan Stills Luger books and has them in stock.
www.Abeboks.com is a good place to search for Luger books.
Which ones.... [img]confused.gif[/img]
Well, it depends on which era you want to collect and study.
For good info and pictures, Jan Still's books are outstanding, then the classics of Kenyon (good pictures also), Datig and Jones, the last two are a bit dated with some incorrect info, but are in my collection and still good books.
I recently bought Regimental Markings, by Jeff Noll,
http://home.earthlink.net/~nopubl/ and although I don't have any marked regimentally, it is a good read and well worth the money.
So, it depends on your era and your tastes. As friends have stated, books cost money, but in the long run will pay dividends. For me, when I started to get serious, I bought books of the Luger I had, then slowly bought a few more. There are other good books and I have bought them as I found "extra money". [img]biggrin.gif[/img]