How to Play Chess Endgames by Karsten Muller and Wolfgang Pajeken. A practical guide to practical endgames rather than an encyclopedia or a course in the basics.
endgame book program

I agree Silman is aimed at people new to studying endgames. The other popular first endgame books are Seirawan and Pandolfini. If you want something a bit more challenging perhaps you would enjoy Seirawan more than the others.
If you don't like Dvoretsky or Fundamental Chess Endings and you already know the basics, you could delve deeper into the most critical endings--pawn and rook endings. "Starting Out: Pawn Endings" and "Starting Out: Rook Endings" are quick and easy reads. "Secrets of Pawn Endings" (Mueller) and "A Practical Guide to Rook Endings" (Minev) require more effort (the extra effort does reap rewards, of course!)
Another option is the new "100 Endgames You Must Know" by Jesus de la Villa. It assumes you already know the basics but want to focus on the most practical endgame theory someone in the 1800-2200 range should learn intimately.
By the way, I wouldn't call Dvoretsk's Endgame Manual a reference book. It's more like a textbook. Comprehensive Chess Endings--now that's a reference! All of these are focused on endgame theory. Don't forget endgame strategy... the gap between middlegames and theoretical endings (How to Play Chess Endgames or Endgame Strategy).

From Dvoretsky's Endgame Manual:
Endgame theory is not a complicated subject to study!
All one needs is a thorough knowledge of a limited number of "precise" positions (as a rule, elementary ones) plus some of the most important principles, evaluations, and standard techniques. The question is, how to select the most important material from the thousands of endings analyzed in various handbooks? That is why this book was written: it offers the basic information you need as the foundation of your own personal endgame theory.
i am trying to figure out the best endgame program using best books available...there is an agreement that SILMAN'S book is the best for beginners (although it says it covers the whole levels but from the majority who read the book there is almost an agreement its excellent for begginers but not as superior for intermediate level), also as referrence books (not to be included in a study program) there are "endgame manual" by DVORETSKY and "fundamental chess endings" by MULLER and LAMPRECHT, NOW as learning books in the middle , those to read from a to z and fill the gap of the middle level ,any suggestions?