
Articles
Please find below helpful articles and white papers:
Pain:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048583/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3401865/
http://www.mayoclinicproceedings.org/article/S0025-6196(12)01170-6/fulltext