1. Modification of tracheal tubes
M. Salim 
British Journal of Anaesthesia 
Volume 90, Issue 4, (April 2003)
DOI: /bja/aeg544
Copyright © 2003 British Journal of Anaesthesia Terms and Conditions

2. Fig 1 Wire being inserted into the proximal side hole.
British Journal of Anaesthesia  , DOI: ( /bja/aeg544)
Copyright © 2003 British Journal of Anaesthesia Terms and Conditions

3. Fig 2 Reshaped endotracheal tubes after insertion of wire.
British Journal of Anaesthesia  , DOI: ( /bja/aeg544)
Copyright © 2003 British Journal of Anaesthesia Terms and Conditions