Review articles or "literature reviews" survey the literature on a give topic or time period. To find review articles, you can search in a journal, such as Annual Reviews dedicated to review articles, or by searching for a topic by keyword and adding terms such as "review" OR "literature review" OR survey (limited to title). In many databases, you should limit your search to "articles/journal" and not to "reviews"—the latter being reviews of particular books rather than review articles. You can also search for dissertations on your topic, which often include extensive literature reviews, many time on subject areas not covered by published literature.