Use keywords and synonyms:
Start by taking keywords directly from your thesis statement.
Use synonyms and related concepts by thinking of other words that mean the same thing as the keywords in your question.
Ex. Civil disobedience or non-violent resistance
Ex. Mahatma Ghandi or Mohandas Ghandi
Ex. law or legal
Ex. permit or allow
Ex. social or society
Ex. reason or justification
Look at the subject terms in your search results and see if you can use any of those.
You can broaden your search results by typing an asterisk symbol * at the end of the root of a word. When you do this, the computer will search for alternative endings for the word you have typed.
For example, perm* yields results for:
permit permits permitted permissible
protest* protests protesting protested protestation
legal* legalize legalized legalization
crim* crime(s) criminal(s) criminalize criminalization