Name Info Provider Link
subscription/membership/fee required Elsevier Science https://linkinghub.elsevier.com/retrieve/pii/00006396-201111000-00030
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=21925793.ui
subscription/membership/fee required Wolters Kluwer https://doi.org/10.1016/j.pain.2011.08.016