Disclaimer: Keywords and their synonyms may vary based on focus of your research question -- if you are looking to identify research where a particular current or out-of-date term was used then using both to search may not be necessary.
Questions to consider before selecting limiters:
Applying common limiters:
Complex search tips:
Searching for journal articles, theses/dissertations, conference proceedings, reports, etc.:
Searching for books and items not found in databases: