Perhaps you should try some spelling variations:
"_ decolonization from" » "_ decolonisation from", "_ decolonization africa", "_ decolonization across"
"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"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("_ decolonization from") or ("its colonization songs"))) or ("city cooperation history"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("_ decolonization from") OR ("its colonization songs"))) OR ("city cooperation history"))*.
• Removing quotes may allow a broader search: (((( _ decolonization from ) or ( its colonization songs ))) or ( city cooperation history ))*.