Perhaps you should try some spelling variations:
"_ decolonization africa" » "_ democratization africa"
"et cooperation history" » "et corporation history", "et federation history", "et cooperations history", "eu cooperation history", "2 cooperation 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.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("_ decolonization africa") OR ("its colonization songs"))) OR ("et cooperation history"))~.
• Removing quotes may allow a broader search: (((( _ decolonization africa ) or ( its colonization songs ))) or ( et cooperation history ))~.
• Adding a wildcard symbol may retrieve word variants: (((("_ decolonization africa") or ("its colonization songs"))) or ("et cooperation history"))*.