| Name | Info | Provider | Link |
|---|---|---|---|
| subscription/membership/fee required | Elsevier Science | https://linkinghub.elsevier.com/retrieve/pii/S0886335001013426 | |
| Cataract | free resource | MedlinePlus Health Information | https://medlineplus.gov/cataract.html |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=11821187.ui | |
| subscription/membership/fee required | Wolters Kluwer | https://doi.org/10.1016/s0886-3350(01)01342-6 |