| Name | Info | Provider | Link |
|---|---|---|---|
| subscription/membership/fee required | Elsevier Science | https://linkinghub.elsevier.com/retrieve/pii/S0166-3542(12)00038-1 | |
| Smallpox | free resource | MedlinePlus Health Information | https://medlineplus.gov/smallpox.html |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=22381921.ui | |
| free resource | PubMed Central | https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22381921/ | |
| free resource | Europe PubMed Central | https://europepmc.org/abstract/MED/22381921 |