| Name | Info | Provider | Link |
|---|---|---|---|
| subscription/membership/fee required | Elsevier Science | https://linkinghub.elsevier.com/retrieve/pii/00006396-199202000-00002 | |
| Pain | free resource | MedlinePlus Health Information | https://medlineplus.gov/pain.html |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=1534163.ui | |
| subscription/membership/fee required | Wolters Kluwer | https://doi.org/10.1016/0304-3959(92)90046-E |