No matter what kind of review project you are doing, you will need to search both the scholarly literature and other materials, like grey literature (discussed below). This page lists common databases searched in evidence synthesis projects, as well as other places to look for materials you may want to include in your review.
There is no set number of resources that you must search for an evidence synthesis project but it is good practice to include at LEAST three databases in your search.
For biomedical topics, it is generally recommended to start your search in either PubMed or Medline and then branch out into other databases. The following are commonly used databases for evidence synthesis projects.
These are not the only databases you can use in your reviews. If you need help deciding which databases will be the best to search for your topic contact the Boxer Library for help!
Grey literature refers to information that hasn't been published commercially or traditionally. In can include, but is not limited to, any of the following:
Grey literature reduces publication bias and can strengthen your review. Like preprints and other sources of information, grey literature should undergo quality assessment before inclusion in your analysis.
Preprint servers are repositories for unpublished research or research in progress that is shared by the researcher with the broader world. This allows for quicker dissemination of information and can also be a way of soliciting peer review or feedback from others in the field. While preprint research may later be published in a traditional journal, articles posted to preprint serves do not appear in most database search indexes.
Because preprints have not gone through a peer-review process it’s important to evaluate the information with care. Many preprints are later published by reputable journals, and a preprint server will indicate if that’s the case.
To find conference proceedings, you'll want to find the websites for professional associations or for whatever conference you are interested in. Often times on their websites you will find a section for proceedings.
Many databases will also include conference proceedings. There may be a format limiter or you can try searching using the name of the conference or including the term "proceedings."
If you are interested in patents registered in a particular country, the easiest thing to do would be to search for that country's patent office on Google and search on their website. For example, searching "japanese patents" on Google will pull up the Japan Patent Office.