Peer-reviewed simply refers to the fact that a journal article has been reviewed by a board of the authors peers before it is published. For example, if a scholar on Thoreau writes an article, the article would be reviewed for accuracy, scholarship, and style by a board of scholars familiar with Thoreau or 19th century American literature.
There are peer-reviewed sources in every field. What field are you looking for?
The library's One Search allows you to limit your results to peer-reviewed sources after you've done a search, see how.
