Perhaps you should try some spelling variations:
"state section" » "states section", "state reaction", "state detection"
"state action" » "state reactions"
"state vector" » "space vector"
"state actor" » "state sector", "state after", "state acts"
"state actors" » "state sectors", "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 action"))) OR ((("state section") OR ("state vector"))))) OR ("state actors")).
• Removing quotes may allow a broader search: (((((( state actor ) or ( state action ))) or ((( state section ) or ( state vector ))))) or ( state actors )).
• Adding a wildcard symbol may retrieve word variants: (((((("state actor") or ("state action"))) or ((("state section") or ("state vector"))))) or ("state actors"))*.