I think an old post by BB had given us GMAT underachievers a study list to improve quant. scores. It is my understanding it started something like this:
1.) Gmat book by Arco- this book nails down the basics
(The book may be a refresher for many, but you forget some of the real easy stuff the GMAT tests. I found this book to be extremelyvaluable)
GRE/GMAT Math review
3.) Official Guide.
I made an attemt to find the Arco book at the local book stores and was unable to do so. Therefore, I ordered it through the web site. (Unsure if Arco was purchased or is owned by Thomson / Peterson's.) However, the book BB was talking about I think may be out of print and I ended up getting the 2nd addition, copywright 2003.
So if anyone is having problem's obtaining the book that was in his post I've made it a little easier...You can track down just about any book with the ISBN # which is as follows: ISBN#:0-7689-1323-3
Hope this is helpful.