1. Ahlgren, J.: An electromyographic analysis of the response to Activator (Andresen-Häupl) therapy. Odont. Revy11 (1960), 125.
2. Ahlgren, J.: The neurophysiological principles of the Andresen method of functional jaw orthopedics. A critical analysis and new hypothesis. Swed. Dent. J.63 (1970), 1.
3. Ahlgren, J.: A longitudinal clinical and cephalometric study of 50 malocclusion cases treated with activator appliances. Trans. EOS 1972, 285.
4. Ahlgren, J.: Pers. Mitt. 1974.
5. Anderson, G. M.: Practical Orthodontics 9. Aufl. C. V. Mosby, St. Louis 1960.