1. Wolf, S. and Wolff, H. G.: Pain. Res. Publ. Ass. Nerv. Ment. Dis., vol. xxii, Williams and Wilkins Co., 1943, pp. 289–300.
2. Palmer, W.: Ibid, pp. 302–326.
3. Jones, C.: Ibid., pp. 274–288.
4. Morley, J.: Abdominal Pain. E. and S. Livingstone, Edinburgh, 1931.
5. Meyer, J., Fetter, D. and Strauss, A.: The Relation of the Pain of Peptic Ulcer to Gastric Motility and Acidity. Arch. Int. Med., 50:338, 1932.