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4. Fine, J. and C. H. W. Lawes: On the muscle-fibres of the anal submucosa, with special reference to the pecten band. Brit. J. Surg.27: 723, 1940.
5. Gabriel, W. B.: The Principles and Practice of Rectal Surgery. Ed. 5, Springfield, Illinois, Charles C Thomas, 1963, p. 290.