Use the connector, AND, in between your different search terms.
Use the connector, OR, in between similar search terms or synonyms.
Enclose search terms with more than one word within quotes to find the exact phrase (e.g., "law enforcement")
Use the truncation symbol (*) to pick up both the singular or plural of a word or all forms of a root wood (e.g., career*)
Search example: "law enforcement" AND (career* OR "vocational guidance")