Perhaps you should try some spelling variations:
"estate sector" » "state section"
"state actions" » "state action", "state reactions", "state functions"
"state actor" » "state action", "state vector", "state sector"
"state actors" » "state actions", "state vectors", "state sectors", "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 ("estate sector"))) OR ((("state actors") OR ("state actions")))).
• Removing quotes may allow a broader search: (((( state actor ) or ( estate sector ))) or ((( state actors ) or ( state actions )))).
• Adding a wildcard symbol may retrieve word variants: (((("state actor") or ("estate sector"))) or ((("state actors") or ("state actions"))))*.