Good Practice in Postoperative and Procedural Pain Management, 2nd Edition July 2012 Pediatric Anesthesia 2012. Volume 22, Issue Supplement s1 Pages 1-79
http://onlinelibrary.wiley.com/doi/10.1111/j.1460-9592.2012.03838.x/pdf
http://onlinelibrary.wiley.com/doi/10.1111/j.1460-9592.2012.03838.x/pdf