| Name | Info | Provider | Link |
|---|---|---|---|
| free resource | Ediciones Doyma, S.L. | https://www.elsevier.es/en/linksolver/pdf/pii/S0001-7310(23)00843-8 | |
| COVID-19 (Coronavirus Disease 2019) | free resource | MedlinePlus Health Information | https://medlineplus.gov/covid19coronavirusdisease2019.html |