I'm not sure what the quality of the books are overall, or the consistency between books, but I've had some luck with introductory level info. It looks like a good start and seems to be the same basic concept as what you describe.
I'm not sure what the quality of the books are overall, or the consistency between books, but I've had some luck with introductory level info. It looks like a good start and seems to be the same basic concept as what you describe.