A scholarly source is a paper or source that is peer-reviewed or published in a peer-reviewed journal or magazine. To determine if something is considered a scholarly source, there are several factors to be considered, including the reputation of the author and publisher, as well as the author's sources.
If the journal or paper is published by a scholarly source, it is considered a scholarly source itself. If the article or journal is reviewed by peers, it is also considered a scholarly source. Evidence-based, well-cited sources for academic audiences may make an article, journal or paper scholarly. Some books are also considered scholarly sources if they are reviewed by peers or published by academic, peer-reviewed publishers.