Johnson DM, From AM, Smith RB, From RP, Maktabi MA. Endoscopic study of mechanisms of failure of endotracheal tube advancement into the trachea during awake fiberoptic orotracheal intubation. Anesthesiology 2005; 102: 910-4.
Branthwaite MA. An unexpected complication of the intubating laryngeal mask. Anaesthesia 1999; 54: 166-7.