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 actors" » "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 sector") OR ("estate sector"))) OR ("state actors")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"state sector\") OR (\"estate sector\"))) or (\"state actors\"))".
• Removing quotes may allow a broader search: (((( state sector ) OR ( estate sector ))) or ( state actors )).
• Adding a wildcard symbol may retrieve word variants: (((("state sector") OR ("estate sector"))) or ("state actors"))*.