What books to get?

I'm looking for something to improve my positional play (I currently play at a ~1700 level with 1.d4) but I don't know what books to would help most with this. I know I want to get a book on Casablanca's games, but which book would be most beneficial? I'd also like to find another book on positional play, and a book on advanced endgames. Any help is appreciated, thanks!

Take a look at this book and the reviews:

http://www.amazon.com/Judgment-Planning-Chess-Max-Euwe/dp/0679143254

Here's an excellent list:

http://www.chessarea.com/chess-instructions/chess-instructions-for-intermediates.html

Because 1700 is a transitional phase between intermediate and advanced you'll probably get something out of these too:

http://www.chessarea.com/chess-instructions/chess-instructions-for-advanced.html

I'd switch out the Euwe book for Heisman's Improving Chess Thinker (primarily a novice book but tells the thought process of class F through master) and Soviet Middlegame Technique.  The Euwe books are great but from what I've seen descriptive only and there are always good modern books coming out.  

I'd also use Soltis' Pawn Structure Chess, not as a replacement for Understanding Pawn Play but as a supplement as both cover different types of pawn structures.  I'd say the Soltis book is a little more advanced as it covers specific pawn structures like the Maroczy Bind and Bolslavsky Wall whereas Understanding Pawn Play covers doubled pawns, backward pawns, pawn chains, isolated pawns, isolated pawn couples, hanging pawns, and pawn islands in general.