Note: As is the case for most professional reviewers, many of the books I review on this site have been provided by the publisher or author, at no cost to me. I've also reviewed books that I bought, because they were worthy of your time. And I've also received dozens of review copies at no charge that do not get reviewed, either because they are not worthy or because they don't meet the subject criteria for this column, or simply because I haven't gotten around to them yet, since I only review one book per month. I have far more books in my office than I will ever read, and the receipt of a free book does not affect my review.