Which book should i get?

I have wanted to buy one of these books for some time

1.Chess Structures-A Grandmaster Guide by Mauricio Flores Rios

2.How To Reassess your Chess by Jeremy Silman

I believe my rating is around 1800.Which one should i buy?

I was unfamiliar with the first, "Chess Structures- A Grandmaster Guide". A reviewer on Amazon said,"This is another sterling offering from Quality Chess. This 464-page book has been authored by a 24-year-old Chilean GM. It looks at strategic plans for white and black in the context of five "families" -- 1) d4 and ...d5, 2) Open Sicilian, 3) Benoni, 4) King's Indian, and 5) French. Each of these families is further subdivided thematically, with each theme receiving a chapter. For instance, d4 and ...d5 is divided into the isolated pawn, hanging pawns, Carlsbad formation, Caro-Kann formation, Slav formation, Stonewall formation, and Grunfeld centre. This first family alone takes up 125 pages of carefully annotated games, each with its own "lesson objective" and "final remarks." In a sense the book is like the tomes, "Mastering the Spanish" by Danny King and "Mastering the King's Indian Defence" by Bellin and Ponzetto except that it covers several structures and its coverage of each is perforce more brief."

That is nothing remotely similar to Silman's popular work. Another Amazon reviewer (of Silman's work) said " The book contents are made up of the following parts: The Concept of Imbalances. Minor Pieces, Rooks, Psychological Meanderings, Target Consciousness, Statics vs. Dynamics, Space, Passed Pawns, and Other Imbalances. Each part is further broken down into specifics and is concluded with a summary and test questions."

They are two completely different works. Silman's work has been quite popular. He is a columnist here. You can read his articles here on Chess.com and see if you like them.  The book on Chess Structures sounds good too.  

Though I haven't seen it, I would guess that "Chess Structures" is a harder work to get through than Silman's book. It would also depend on whether or not you play openings in one of the five "families" he covers. 

Why not read both?

// I found an excerpt of Chess Structures at its publishers website.

@notmtwain,Both of them are really instructive.Silman's articles are awesome,he has a huge fanbase.Mauricio has created a chess website for his book alone(!),chess-structures.com and has 12/12 5 star reviews on amazon.com.I was just wondering which book would be better suitedfor my rating range as my limited allowance allows me to buy a book per two months.Thanks for the input :).

@pfren Thanks for the IM suggestion :),im gonna buy Chess Structures

Depends on what you mean by "1800"

Is that 1800 on chess.com? 1800 FIDE? 1800 some other organization.  The answer will determine which book is more suited for you.  I just recently bought Chess Structures-A Grandmaster Guide by Mauricio Flores Rios, and love it.  

You're not even 1800 in a single chess.com pool, I somehow doubt you're rated 1800 in any federation...

none buy diamond

I dont play on chess.com anymore,my computer lags a lot,im 1860 on lichess which is slightly inflated so i take it as 1800.

https://web.archive.org/web/20140708095832/http://www.chesscafe.com/text/review769.pdf

https://chessbookreviews.wordpress.com/tag/chess-structures-a-grandmaster-guide/

lichess is more inflated than that

Waterstriker, did you work through it?

Simple Chess: A great explanation of strategy, making it very easy to understand. You have it on YT as well: https://www.youtube.com/playlist?list=PLUrgfsyInqNbkyiwPSSBQ6ALkkccKItPE

Good Chess Books for Beginners and Beyond...

https://www.chess.com/blog/RussBell/good-chess-books-for-beginners-and-beyond

https://www.chess.com/blog/RussBell