Do not waste your time and money to buy book. I used a lot of commercial books like Sicilian, Hiarcs, Japan Top Team, S.W.Y.D, Probox, 1337chess.....They were all strong but for a short time of period.
We are lucky there are punch of free strong books here with new updates almost every day. Try it my friend. The free book author they just need your help of testing theirs and send them pgn file no matter lose or win result.