RT Journal Article SR Electronic T1 The Effect of Extension of the Head and Neck upon the Infrahyoid Respiratory Passage and the Supraclavicular Portion of the Human Trachea JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 176 OP 180 DO 10.1136/thx.14.2.176 VO 14 IS 2 A1 R. S. Harris YR 1959 UL http://thorax.bmj.com/content/14/2/176.abstract AB