We are often asked to recommend a short list of good first books to read on the many subject areas we feature. In the past, our subject lists by author did not distinguish entry level books in any way, and put them side by side with more professional, highly detailed works. Many interested people have given up in confusion when confronting these long lists, which is certainly not our goal.

Now we mark books which can be read as good first books or introductions. These are marked "A good choice as a first book or introduction for self-study". By designating a book this way we do not mean to imply that the book is simplistic or unsophisticated. In general, the books that do not carry this designation are works that contribute to the topic in a more detailed manner and would be best understood after having read more introductory works. We welcome your suggestions as we continue to refine this distinction.