Name Info Provider Link
subscription/membership/fee required Ovid Technologies, Inc. http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=18950449.ui
subscription/membership/fee required Wiley https://doi.org/10.1111/j.1526-4637.2008.00515.x
subscription/membership/fee required Silverchair Information Systems https://academic.oup.com/painmedicine/article-lookup/doi/10.1111/j.1526-4637.2008.00515.x