Maxwell LG, Buckley GM, Kudchadkar SR, Ely E, Stebbins EL, Dube C, Morad A, Jastaniah EA, Sethna NF, Yaster M. Pain management following major intracranial surgery in pediatric patients: a prospective cohort study in three academic children's hospitals. Paediatr Anaesth. 2014 Nov; 24(11):1132-40.