Most search engines have advanced search features or tips for better searches, allowing you to be more specific with your search and refine your search results. You can use the following search limits and more:
If the search engine does not have a separate advanced search screen, use the search filters that appear on the search results page.
Once you find an article in a library database or on the web that works perfect for your paper. Search for that article title with quotes, and you will return other papers on the web that contain your paper in their bibliographies. You can then scan their bibliographies for more papers on your topic.
Use truncation symbols for root spelling variations (e.g. cultur* retrieves culture, cultures, cultural, culturally, etc.)
Use synonyms of your search term (e.g. multicultural, cultural differences, diversity describe the same concept)