Jungbauer A, Schumann M, Brunkhorst V, Börgers A, Groeben H. Expected difficult tracheal intubation : a prospective comparison of direct laryngoscopy and video laryngoscopy in 200 patients. Br J Anaesth 2009 ; 102 : 546-50.
Kaplan MB, Hagberg CA, Ward DS, Brambrink A, Chhibber AK, Heidegger T, et al. Comparison of direct and video-assisted views of the larynx during routine intubation. J Clin Anesth 2006 ; 18 : 357-62.