Societies of the Alexander Technique: 

http://www.canstat.ca/

http://www.amsatonline.org/

Health Publications:

Chronic Back Pain                                                         http://www.bmj.com/content/337/bmj.a884

Parkinsons Disease                                                                                 http://journals.sagepub.com/doi/abs/10.1191/0269215502cr544oa

Harvard Medical School  https://static1.squarespace.com/static/569dc3a5b20943556a9b9ddb/t/56eef55d2fe13198fee0004b/1458500960325/Harvard+Health+Blog+on+AT.pdf 

Videos about the Technique: 

https://youtube.com/watch?v=uwS3RzwbvpE%3Fstart%3D0%26end%3D44