1. Inberg, H O & Prust, F W (1968). Arch. Phys. Med. & Rehab. 49, 343.
2. Langenback, R J (1969). Gastro-intestinal problems. In Spinal Cord Injuries, ed. By D. Ruge, pp. 115–117. Springfield, Illinois: Charles C. Thomas (1969).
3. Wanebo, H J, Webb, E & Combs, R (1965). California Medicine, 103, 193.