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How you play the Queens gambit declined

Try the exchange variation of the Queens Gambit declined. Don't commit Nf3 and wait to play first Bd3 and then Ne2 so to be able have a pawn break on the center with f3 and a timed e4.
Move order: d4,c4,Nc3,cxd5,Bg5,Bd3,Ne2 e.t.c Find the classic of Botvinnik and Kasparov on this or read the book 1.d4 of Schandorf and QGD of Mathew Sadler it's very informative and written in educative style.

Get this one:
https://www.amazon.com/Queens-Gambit-Declined-Matthew-Sadler/dp/1857442563
It's a very strong candidate on the best openings' book ever written.
Recently I got interested in this opening therefore I commonly use the 1d4 opening to get this line but I found a bit of problems in this opening when I reach the midddlegames or sometimes in the opening itself when there are unusual ways they confuse me for those who don't know this is the line(1.d4,d5 2.c4,e6 )this is the queens gambit declined the common line I like is 3.Nf3,Nf6 4.Bg5 or Nc3 to go in the ragozin defence. For those who have a wide experience in this opening can you give me an opinion about this line and some side lines which I can commonly view in this opening