PubMed is a free website that allows users to search for biomedical and health literature. It combines indexing from the National Library of Medicine with updates from science publishers and societies.
The basic search in PubMed will guide your keywords if you enter a single search topic.
Or, if you know a little about Boolean Operators (AND, OR, or NOT), you can use the ADVANCED SEARCH.
Also, experiment with truncation. Take a word stem and add an asterisk (*) after the last letter. This search will retrieve multiple endings to your word--example, gene* will bring back genes, genetic, genetics, etc.
Here's a sample entry from the results screen. If you click on the title, you will see a full page display of that record.
Note the "Download PDF" button will appear if you install the LibKey Nomad browser extension on your computer.
Boss around those results with filters. They will reduce the number of matches so use them wisely.
You can filter by date, article type, participants, language, and more.
keep looking down and explore the Additional filters!
A handy feature of PubMed is a filter on publication type. Besides finding lots of research articles, you may see "Review" and "Systematic Review" and not know the difference.
See What's in a name: the difference between systematic review and literature review and why it matters by Lynn Kysh