You have to buy Q-bank directly from Kaplan. It is a internet computer based set of ovwe 2,000 questions. It is customizable and you get a unique user ID and password for access. It cost like $100 for 1 month of access or like $200 for 3 months.
Kaplan also has Q-book which has about 350 good questions in it. You might can find a copy of that book from an upper classman what bought Kaplan stuff. I don't think Kaplan offers Q-book as a stand alone product. It integrated into all their other packages (like Med Pass, etc).
Good Luck in studying for the boards.
