You also can find peer-reviewed articles in Google Scholar:
Peer-reviewed articles in Google Scholar may not be free and full-text. To limit your search to full-text, follow your search terms with the file-type limiter as in the example above.
How do you know if the article is peer-reviewed? Clues include:
If in doubt, Google the publication title to see if you can find a description that says if it is peer-reviewed; or Ask a Librarian.