If you are looking for scholarly (a.k.a. peer-reviewed, academic, or refereed) journal articles on any economics topic, these databases are the best place to start -- in this order:
If you have one specific citation, like this:
Use this Find Journals tool to search for the journal name first -- in this case, the Journal of Economic Perspectives -- then browse or search within that journal to find the specific article.
Most of the content in these databases is NOT peer-reviewed, and thus may not be usable for your capstone. However, it can be useful if you need to research how an economic topic is being presented to the general, i.e. non-economist, public.
The biggest difference between scholarly and popular (e.g., newspapers, magazines) sources is that scholarly sources go through a rigorous quality check before being published, a process called Peer Review. Watch the video below to learn about it.