Perhaps you should try some spelling variations:
"state action" » "state reactions", "state actors"
"state sector" » "estate sector", "state vectors", "state section"
"state vector" » "space vector"
"state afters" » "state after", "state matters", "state actors"
"state actor" » "state actors", "state after", "state acts"

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