Queen's Gambit Declined: Catalan Opening

1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.g3 Bb4+ 5.Bd2 Be7 6.Bg2 c6 7.Qc2 Nbd7 8.O-O O-O 9.Bf4 a5 10.Rd1