(A09) Accepted
1. Nf3 d5 2. c4 dxc4
(A09) Keres
1. Nf3 d5 2. c4 dxc4 3. e3 Be6
(A09) Advance
1. Nf3 d5 2. c4 d4
(A09) Polonaise
1. Nf3 d5 2. c4 d4 3. b4