Perhaps you should try some spelling variations:
"state detectors" » "state detection", "wave detectors", "feature detectors"
"state sector" » "estate sector", "state section", "state sensor"
"state vectors" » "space vectors"
"state vector" » "space vector"
"state actor" » "state action", "state after", "state acts"
"state actors" » "state actions", "state afters", "state actss", "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 ((("state vectors") OR ("state detectors"))))) OR ("state vector"))))) OR ("state actors"))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"state actor\") or (((((\"state sector\") or (((\"state vectors\") OR (\"state detectors\"))))) or (\"state vector\"))))) or (\"state actors\"))*".
• Removing quotes may allow a broader search: (((( state actor ) or ((((( state sector ) or ((( state vectors ) OR ( state detectors ))))) or ( state vector ))))) or ( state actors ))*.