| Name | Info | Provider | Link |
|---|---|---|---|
| subscription/membership/fee required | Ingenta plc | https://www.ingentaconnect.com/openurl?genre=article&issn=&volume=67&issue=3&spage=vii&aulast= | |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=39061122.ui | |
| subscription/membership/fee required | Wolters Kluwer | https://dx.doi.org/10.1097/01.grf.0001027868.24479.b9 |