D06Black7 book lines continue
Austrian Defense, Gusev Countergambit
Queen's Gambit Declined1. d4 d5 2. c4 c5 3. cxd5 Nf6
Also known as QGD: Austrian, Rubinstein Variation, Queen's Gambit Refused: Austrian Defense, Gusev Countergambit, Queen's Gambit Refused, Austrian Defense.