Many scholarly journal articles are subject to peer review.
Before they are published, articles that are peer reviewed or refereed are read and critiqued by other historians.
Search in Ulrich's to find out whether a journal is peer reviewed.
When you're getting started, try searching Discovery Service using keywords that describe your topic, ie:
Find out where an article or a book has been cited.
Why? To find more recent research building on the book or article you have.