Perhaps you should try some spelling variations:
"city cooperation history" » "city corporation history", "city federation history", "china cooperation history", "city corporations history"
"its colonization songs" » "its colonization still", "its colonization work", "its decolonization notes", "anti colonization songs", "jews colonization songs", "mars colonization songs"
"de cooperation still" » "de cooperation scale", "de cooperation state", "de cooperation studies", "2 cooperation still", "trade cooperation still", "area cooperation still"

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: (((("its colonization songs") OR ("de cooperation still"))) OR ("city cooperation history"))~.
• Removing quotes may allow a broader search: (((( its colonization songs ) or ( de cooperation still ))) or ( city cooperation history ))~.
• Adding a wildcard symbol may retrieve word variants: (((("its colonization songs") or ("de cooperation still"))) or ("city cooperation history"))*.