1. Analgesic efficacy of tramadol 2 mg kg−1 for paediatric day-case adenoidectomy 
H Viitanen, P Annila 
British Journal of Anaesthesia 
Volume 86, Issue 4, Pages (April 2001)
DOI: /bja/
Copyright © 2001 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Number of pethidine doses required in the recovery room in the tramadol and placebo groups (P=0.014).
British Journal of Anaesthesia  , DOI: ( /bja/ )
Copyright © 2001 British Journal of Anaesthesia Terms and Conditions