1. Adler, E.: Der Zigarettenmagen.Med. Klin., 21:1005–1006, July 3, 1925.
2. Wagner, F.: Nicotine and Duodenal Syndrome.Med. Klin., 20:555, 1924. Abs.Jour. A. M. A., 82:1903, 1924.
3. Gray, I.: Tobacco Smoking and Gastric Symptoms.Ann. Int. Med., 3:267–277, 1929.
4. Cushing, H.: Peptic Ulcers and the Interbrain.S. G. O., 55:1–34, July, 1932.
5. Sacchetto, I., and Testolin, M.: Behavior of Gastric Secretion During Smoking.Minerva Med., 7:807–814, July 31, 1927.