"Practical Chess Exercizes" by Ray Cheng

The day before yesterday I purchased the Amazon's Kindle version of the book "Practical Chess Exercizes" by Ray Cheng.
A few seconds after I sent my order & payment, the e-book was available on my Kindle. Amazing! 

This work is the demonstration that one doesn't need to be a strong player in order to publish a useful and well written chess book. Also I love this Kindle edition. For instance see problem n° 4 as shown on my electronic device. White's winning move and a detailed explanation starting from 1.Kb2 is shown on the next Kindle page. As you can see the diagram is large and I can see it comfortably. Furthermore, the book deals with tactics, endgames, strategy and much more and nowhere you are told in advance the kind of problem you are facing, just like it happens in tournaments.
After I read 10 problems, I guess that the book is suitable for  players ranging from Fide rating 1500 to Fide rating 2.000.
A good book at an affordable price. I hope Mr. Cheng is writing a sequel now :-)
Here you can see some reviews of this book:
www.chesscafe.com/text/review595.pdf

http://www.chessville.com/reviews/PracticalChessExercises.htm
http://chessconfessions.blogspot.it/2007/09/review-practical-chess-exercises.html
Amazon's customers book review BTW here you can read a preview as well