Peer-reviewed articles are found in academic/ scholarly journals* and databases. These journals are articles written by an expert in the given field and reviewed by other experts and scholars in the field. This level of vetting is a way to ensure that the article represents the best research practices in the field.
*An academic/ scholarly journal is a professional publication on a specific subject in which most articles are published through a peer-review process (book reviews and letters to the editors are example of non-peer reviewed articles in an academic journal).
Here are some helpful tools that can help you select the sources you need:
You can use OneSearch to help you find peer-reviewed articles, which is what is shown below. You can also find peer-reviewed articles in databases (list is located on the "Databases" tab). Some of these databases have a similar filter feature that will allow you to do a search and select only peer-reviewed journals.
You can start doing a keyword search in OneSearch:
You can use the filters on the left hand side to narrow your search results to "Peer-reviewed Journals." I also checked "Full-text online" to find materials only listed online. Then click "Apply Filters."
The results will regenerate and provide you with peer-reviewed material. Another easy way of seeing if an article is from peer-reviewed journal is by the purple icon listed under the article title and author. NOTE: Just because an article is in a peer-reviewed journal, does not automatically mean it is peer-reviewed. It may be a book review or an editorial, which is not a peer-reviewed article.