A scholarly journal contains articles and letters written by scholars to report results of research and other scholarly activities. For most academic papers, scholarly articles are excellent and prefered sources for supporting your arguments. Scholarly journals are usually published or sponsored by a professional society or association. There may be a list of reviewers on the first few pages. Refereed and juried journals tend to be considered the best in their field.
Illustrations are typically charts, graphs, tables, formulas.
The author's credentials are listed. A bibliography or list of references is at the end of the article.