Chess books about Pawn Endgames

King and pawn endgames involve only kings and pawns on one or both sides. Cecil Purdy said "Pawn endings are to chess as putting is to golf."
Getting a passed pawn is crucial (a passed pawn is one which does not have an opposing pawn on its file or on adjacent files on its way to promotion). Nimzovich once said that a passed pawn has a 'lust to expand'. An outside passed pawn is particularly deadly. The point of this is a decoy — while the defending king is preventing it from queening, the attacking king wins pawns on the other side.

Opposition is an important technique that is used to gain an advantage. When two kings are in opposition, they are on the same file (or rank) with an empty square separating them. The player having the move loses the opposition. He must move his king and allow the opponent's king to advance. Note however that the opposition is a means to an end, which is penetration into the enemy position. If the attacker can penetrate without the opposition, he should do so.