Perhaps you should try some spelling variations:
"states factors" » "estates factors", "stages factors", "status factors"
"state vectors" » "state actors", "state detectors", "space vectors"
"state factors" » "state actors", "state factor", "state factory"
"state vector" » "space vector"
"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 vectors") OR ("state vector"))))) OR ((("state factors") OR ("states factors")))).
• Removing quotes may allow a broader search: (((( state actor ) or ((( state vectors ) or ( state vector ))))) or ((( state factors ) or ( states factors )))).
• Adding a wildcard symbol may retrieve word variants: (((("state actor") or ((("state vectors") or ("state vector"))))) or ((("state factors") or ("states factors"))))*.