here are a few
Uston's Million Dollar BJ, Griffin's Theory of BJ, Wong's Professional BJ, Schlesinger's BJ Attack, along with the main book on your system. At the very least you will need these to reference in order to take part in more serious discussions, which is a necessary part of learning unless you are lucky enough to already be in a circle of advanced players who will take you by the hand.
I'd have either SBA & BJRM, or the Qfit products which can do everything. I would belong to a serious discussion group where you can talk about your sim results rather than drawing your own conclusions. It is very easy to misunderstand output, have settings incorrect, etc.