Pawn Power in Chess by
Hans Kmoch, but I can hardly understand what he is trying to convey in the book. Maybe this has to do with my level of play or maybe it has to do with the way
Kmoch writes. I do not have
Soltis' book, so I was curious to know if anyone has read it and if it is similar to
I haven't read either but here's an excerpt from Dan Heisman's Novice Nook #17
A "break" move is a pawn move that “breaks up” an opponent's (fixed) pawn chain by attacking the opponent's pawns with that pawn. In his classic work Pawn Power in Chess, Hans Kmoch calls this move a liberation lever. Don’t be put off by Kmoch’s arcane nomenclature – Pawn Power is a great book for players in the 1300-1900 rating range.
 Current world champion Viswanathan Anand also mentioned the book in this interview.
Hope this helps for something... I'm also thinking of buying one of these two books.
“Pawn Structure Chess” by Andrew Soltis is reasonably clearly written and should be not too hard to understand. I enjoyed it when I was rated about 1900-2000.