Imre Hera and Ufuk Tuncer, A Cutting-Edge Gambit against the Queen's Indian (New in Chess 2014). 174 pp., €19.95/$24.95.
This book is a dense monograph dedicated entirely to the theoretically hot gambit line 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6 5.Qc2 c5 6.d5. It was first played (as far as I can tell) by Levon Gregorian against Paul Keres in the 1967 USSR Team Championship, but only hit the bigtime in a mainstream way after 2006, when Mamedyarov used it against Gelfand and Aronian employed it against Leko. By 2007 it was hot and by 2008 everyone was using it. It may have cooled off a bit from its high point, but it's still popular, important and not fully solved.
One reason this is an important line is that once Black has committed to a Queen's Indian, there aren't too many reasonable ways for him to avoid this gambit. Moreover, once 1.d4 Nf6 2.c4 e6 3.Nf3 is on the board, 3...b6 is likely to arise. Some professionals prefer 3...d5, transposing to the Queen's Gambit family, but at the club level most players who want a Queen's Gambit will head for it on move 1. The other reasonable option is 3...Bb4+, the Bogo-Indian. This book won't help you with that one, but they do offer brief coverage of Black's alternatives on moves 4 and 5. All in all then, this book may not offer a full opening repertoire with 1.d4 or even for 1.d4 Nf6 2.c4 e6 3.Nf3, but it does offer a big chunk of such a repertoire.
The book has two main authors - GM Imre Hera and FM Ufuk Tuncer - and has a glowing foreword by Alexey Shirov. Shirov praises the book as a book on "modern chess": the authors go very deeply, push theory along, and (so they say, and Shirov concurs) don't keep any secrets.
Whether they have really kept any secrets isn't something I can judge, but what I can say from checking some of their lines with the computer and with recent games is that their work is thorough, accurate and creative.
It's a very good book, but who is it for? Definitely not the average club player: the material is very dense - this is not "wash and wear" material. It's clearly suitable for titled players who grapple with this line, and for correspondence players too. I'd say that tournament players rated 2000 (more likely, 2100-2200) and up could benefit from it, but it will take some hard work. I can heartily recommend the book, but only to serious tournament players and of course their brethren in correspondence chess.