I lifted this from a yahoogroup I belong to ... thought you might find it interesting:
From: Jim Francis
Date: Fri Dec 9, 2005 11:58 am
Subject: Re: [Chess_Library] Book in Chessbase format
I have found this awesome site...It has games for chessbase and fritz...from old out of print books...but none the less awesome!
This guy is a genius and if you have ever read a chessbook and said the variations would be easier to see if they were on a computer rather than try to keep up with a given position this is for you...now mind you you must own the text in order to get the most out of it but the games (in most cases) are playable and enjoyable...the exception is Euwe's middlegame series...which he completely annotates so he tests you by asking you for a password enclosed in the text but this site is awesome...
http://www.uni-klu.ac.at/~gossimit/c/book.htm
Best of luck