Peer review is the process by which articles are selected for publication in academic/scholarly journals. The articles are evaluated for accuracy, proper research methodology, and the correct interpretation and use of data by other experts in the field. No other publications undergo this level of vetting.
If you are looking for peer reviewed articles, one way is to limit your database searches to only articles in peer reviewed publications. Many databases allow you to do this. For example, most databases have a box labeled "Scholarly" or "Peer Reviewed" in the limiters section under the main search boxes.