This book is a disappointment. The actual content is slim. The book has lots of white space, lots of self tests for readers, lots of blank charts for the reader to fill in as he or she plans a course, lots of bulleted "to do" lists. But it provides virtually no supporting information for any of its points or suggestions and offers no sense that Dl is actually a pretty complicated subject. In addition, it offers no references, bibliographical material, or any other support for the readers' continued learning.