There are several ways to find primary and secondary source articles. One option is OneSearch, which contains both kinds of articles:
Depending on your topic, it may make sense to search one database at a time. These database contain both primary and secondary sources in the science and medical fields:
Comprehensive database for chemistry and other fields, including biochemistry, chemical engineering, materials science, nanotechnology, physics, environmental science, and engineering.
In the sciences, primary and secondary sources may look very similar at first glance. It may be helpful to use a database that clearly labels primary vs. secondary sources, or gives you a way to search for only one or the other. The following databases have options that make this process easier for you:
Contains research and scholarly information in the fields of nursing and allied health. Additional resources include evidence-based care sheets, quick lessons, and continuing education modules.
Contains more than 37 million citations and abstracts of biomedical literature. Full-text articles are often available as links to other sources, such as the publisher's website or PubMed Central (PMC).