Perhaps you should try some spelling variations:
"state sectors" » "state vectors", "estate sektors", "state reactors", "state vectorss", "state sections", "state sensors"
"estate sector" » "state section", "estate vectors", "estate section", "estate sensor"
"state sector" » "state vectors", "state section", "state sensor"

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