1. The Esophagus and Pharynx in Action: A Study of Structure in Relation to Function;Lerche,1950
2. A study of the arrangement of the muscular fibers at the upper end of the esophagus;Birmingham;J Anat Physiol,1899
3. The larynx and pharynx radiologically considered;O'Bannon;Southern Med J,1954
4. The arrangement of the longitudinal and circular musculature at the upper end of the oesophagus;Abel;J Anat Physiol,1913
5. A study of the cricopharyngeal sphincter in man and in the dog;Lund;Ann R Coil Surg Eng,1965