1. The arrangement of the longitudinal and circular musculature at the upper end of the oesophagus;Abel;J Anat Physiol,1913
2. A study of the arrangement of the muscular fibres at the upper end of the oesophagus;Birmingham;J Anat Physiol,1899
3. Upper esophageal sphincter: pre and post-laryngectomy-a normative study;Gates;Laryngoscope,1980
4. Motor nerve supply to the cricopharyngeal sphincter;Lund;Ann Otol Rhinol Laryngol,1964
5. Structure of the esophagus in the adult opossum, Didelphis Virgiana;Marklin;Anat Anz,1979