Perhaps you should try some spelling variations:
"estate sector" » "state section"
"state factors" » "states factors", "state actors", "state factor"
"state sensor" » "state sensors", "rate sensor", "image sensor"
"state actor" » "state actors", "state action", "state sector"

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 sensor") OR ("estate sector"))) OR ("state vector"))))) OR ("state factors")).
• Removing quotes may allow a broader search: (((( state actor ) or ((((( state sensor ) or ( estate sector ))) or ( state vector ))))) or ( state factors )).
• Adding a wildcard symbol may retrieve word variants: (((("state actor") or ((((("state sensor") or ("estate sector"))) or ("state vector"))))) or ("state factors"))*.