1. Draper DO, Jutte SL, Knight KL. Therapeutic Ultrasound: The Art and Science. Wolters Kluwer, Baltimore.
2. Kuitert JH. Ultrasonic energy as an adjunct in the management of radiculitis and similar referred pain. Am J Phys Med. 1954;33(1):61-65.
3. Nwuga VCB. Ultrasound in treatment of back pain resulting from prolapsed intervertebral disc. Arch Phys Med Rehabil. 1983;64(2):88-89.
4. Soren A. Evaluation of ultrasound treatment in musculoskeletal disorders. Physiotherapy. 1995;81:214-217.
5. Aides JH, Jadeson WJ. Ultrasonic energy in the treatment of hypertrophic arthritis in elderly patients. Ann W Med Surg. 1952;6(9):545-550.