| Name | Info | Provider | Link |
|---|---|---|---|
| Endoscopy | free resource | MedlinePlus Health Information | https://medlineplus.gov/endoscopy.html |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=14511227.ui | |
| subscription/membership/fee required | Wiley | https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0143-2885&date=2003&volume=36&issue=10&spage=691 |