Chess books about Queen's Gambit

The Queen's Gambit, 1.d4 d5 2.c4, is one of the most important chess openings, popular at all levels of play from novice to World Champion. White's second move aims to divert black's pawn from the centre. Unlike the King's Gambit, in which white risks remaining a pawn down on a permanent basis, the Queen's Gambit does not really sacrifice a pawn; it is always possible for white to recover his investment, though there are lines where white makes it a permanent sacrifice. Black generally supports his d5-pawn by either 2...c6 or 2...e6, or else plays 2...dxc4, the Queen's Gambit Accepted.
In the Queen's Gambit Accepted, black concedes a little ground in the centre, hoping that his free and easy development will see him through. It leads to lively piece-play, and gives rise to a considerable diversity of central structures.
If black decides not to take on c4 and plays the solid e6, the game transposes to the Queen's Gambit Declined. The Classical Queen's Gambit, 1.d4 d5 2.c4 e6, is rather passive for black, and gives white a variety of attacking options. Black can rarely hope for more than a draw. On the other hand, black's position is highly resilient.

from Nunn's Chess Openings.