Most of the databases have tools to help you limit your search. In OneSearch and the EBSCO databases for example, you can limit your search by publication date or source type. You can limit your results to Scholarly (Peer Reviewed) Journals using the tools on the left-hand side of the screen. However, do NOT limit your search at the beginning of your research. You should use limiters like "scholarly peer-reviewed articles" after you've looked at all types of results for keywords and ideas that will help you construct the most effective searches.
You can also click on Show More above to limit to your choice of publication sources.
You can use the drop down search field to narrow your search. For example, the SUBJECT field contains terms that were deemed to be important keywords that describe the primary subject content of the article or book. Always start by NOT limiting your search field so you can see everything in your search results. Use the field limiters if you retrieve too many results. You can try Subject or Abstract (summary) to retrieve less results.
You can use the drop-down menu in the search boxes to select a single field to search. In the example above, by choosing SUBJECT, your results will only have the terms you are searching in the Subject field as in the result below,
ABSTRACT, the summary, is another useful field if you want to narrow your search by field to hopefully reduce the number of results to more relevant items.