Primary sources are empirical studies (they report research through observable testing) that are peer-reviewed, often published in journals, and usually include standardized sections (Abstract, Introduction, Methods, Results, Discussion, References).
Databases contain an index to journals and articles that you can search to identify articles on your topic. Some databases link to the full text of journal articles. If the full text is not available from the database, check the library Citation Linker to see if Reed has access to the article. If the article you are looking for is not available at Reed, you can request it through interlibrary loan.