book... Travell & Simons: Myofascial Pain and Dysfunction: The Trigger Point Manual

These volumes are "the Bible" for trigger point therapists. If you get really serious about treating trigger points, you'll buy these books, but there are less expensive options to start your studies. Janet Travell pioneered the medical discipline called trigger point injection therapy. Along with David Simons, she filed these volumes with the results of 40 years of clinical research.