1. Abel, A. L.: The pecten: the pecten band; pectenosis and pectonotomy.Lancet, 1: 714–719, April, 1932.
2. Carnett, J. B.: Chronic anal sphincterismus as a cause of constipation.Surg, Clin. N. Amer., 10: 1319–1323, Dec, 1930.
3. Hill, T. C. and Hayden, E. P.: Chronic constipation due to congenital stenosis of the anal canal.New England Jour. Med., 199 : 552–554, Sept. 20, 1928.
4. Mayo, Herbert: Observations on injuries and disease of the rec bum. London, Burgess and Hill, 220 pp., 1833.
5. Miles, W. E.: Observations upon internal piles.S. G. O., 29 : 497–506, Nov., 1919.