Organize your keywords by writing them out or storing them
Connect these keywords using the words AND (to narrow); OR (to broaden); NOT (to exclude)
For example (higher education OR universit* OR college* OR academi*) AND (accessib* OR disabl* OR ableism OR ADA OR able OR handicap OR impair* OR *body related ability")
Find relevant articles, take note of their subject terms and transfer them to your own searches