Keela Herr, Marita Titler, Perry Fine, Sara Sanders, Joe Cavanaugh, John Swegle, Chris Forcucci, Xiongwen Tang
J Pain Symptom Manage.
Author manuscript; available in PMC 2011 May 1.Published in final edited form as: J Pain Symptom Manage. 2010 May; 39(5): 803–819. doi: 10.1016/j.jpainsymman.2009.09.025