Perhaps you should try some spelling variations:
"state sector" » "estate sector", "state vectors", "state section"
"state vector" » "space vector"
"state actor" » "state action", "state acts", "state vectors"
"state actors" » "state actions", "state actss", "state vectorss", "state factors"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((((("state actor") OR ("state after"))) OR ((("state sector") OR ("state vector"))))) OR ("state actors"))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"state actor\") OR (\"state after\"))) or (((\"state sector\") or (\"state vector\"))))) or (\"state actors\"))*".
• Removing quotes may allow a broader search: (((((( state actor ) OR ( state after ))) or ((( state sector ) or ( state vector ))))) or ( state actors ))*.