Perhaps you should try some spelling variations:
"area cooperation studies" » "area cooperation series", "area cooperation sources", "area cooperation implies", "asian cooperation studies", "border cooperation studies", "china cooperation studies"
"_ colonization failed" » "_ colonization still", "_ organizations failed", "_ decolonization failed", "decolonization _ failed"
"early operation state" » "early generation state", "day operation state", "early observations state", "early operations state", "early operation stage", "early cooperation state"

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: (("area cooperation studies") OR ((("early operation state") OR ("_ colonization failed"))))~.
• Removing quotes may allow a broader search: (( area cooperation studies ) or ((( early operation state ) or ( _ colonization failed ))))~.
• Adding a wildcard symbol may retrieve word variants: (("area cooperation studies") or ((("early operation state") or ("_ colonization failed"))))*.