| 1 | Medical databases | PubMed |
| Scopus (which includes Embase and MEDLINE) | ||
| TRIP | ||
| Cochrane | ||
| 2 | Guideline developer website | NICE |
| SIGN | ||
| National Library of Medicine—National Institute of Health (USA) | ||
| Canadian Medical Association Infobase | ||
| NewZealand Guidelines Group | ||
| Guidelines International Network | ||
| National Guidelines Clearinghouse | ||
| 3 | Expert contributions/websites of specific societies |