| Name | Info | Provider | Link |
|---|---|---|---|
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=18499608.ui | |
| subscription/membership/fee required | Wolters Kluwer | https://doi.org/10.1213/ane.0b013e31816f2004 |