| Name | Info | Provider | Link |
|---|---|---|---|
| free resource | Elsevier Science | https://linkinghub.elsevier.com/retrieve/pii/S0032-5791(19)30048-3 | |
| Vaccines | free resource | MedlinePlus Health Information | https://medlineplus.gov/vaccines.html |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=30561723.ui | |
| subscription/membership/fee required | Silverchair Information Systems | https://academic.oup.com/ps/article-lookup/doi/10.3382/ps/pey559 |