Perhaps you should try some spelling variations:
"estate sector" » "state section", "estate vector", "estate vectors", "estate section"
"state sector" » "state vector", "state vectors", "state section"
"state actor" » "state action", "state vector", "state after"
"state actors" » "state actions", "state vectors", "state afters", "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 sector") OR ("estate sector"))))) OR ("state actors")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"state actor\") or (((\"state sector\") OR (\"estate sector\"))))) or (\"state actors\"))".
• Removing quotes may allow a broader search: (((( state actor ) or ((( state sector ) OR ( estate sector ))))) or ( state actors )).
• Adding a wildcard symbol may retrieve word variants: (((("state actor") or ((("state sector") OR ("estate sector"))))) or ("state actors"))*.