There are search tips/strategies that can be used to in pretty much any database to help you broaden or narrow down your search when finding articles for your SSP.
This presentation reviews these tips: Search Strategies Revisited (for NUR455).
This same presentation was given (and recorded) during NUR480 in the Spring 2015 semester. Click here and fast forward to 6 minutes 15 seconds if you'd like to watch/listen.
Here's a list of databases you may want to search to find articles for your SSP: