Perhaps you should try some spelling variations:
"state vectors" » "state actors", "state detectors", "space vectors"
"state factors" » "states factors", "state actors", "state factor"
"state vector" » "space vector"
"state after" » "state actors"

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 after") OR ((("state vectors") OR ("state vector"))))) OR ("state factors")).
• Removing quotes may allow a broader search: (((( state after ) or ((( state vectors ) or ( state vector ))))) or ( state factors )).
• Adding a wildcard symbol may retrieve word variants: (((("state after") or ((("state vectors") or ("state vector"))))) or ("state factors"))*.