Perhaps you should try some spelling variations:
"_ decolonization across" » "_ decolonization africa", "_ decolonization case", "_ decolonization from"
"africa colonization failed" » "arrival colonization failed", "africa cooperation failed", "africa organization failed", "africa colonization still", "africa organizations failed"
"its cooperation history" » "its corporation history", "its federation history", "city cooperation history", "et cooperation history"

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 across") OR ("africa colonization failed"))) OR ("its cooperation history"))~.
• Removing quotes may allow a broader search: (((( _ decolonization across ) or ( africa colonization failed ))) or ( its cooperation history ))~.
• Adding a wildcard symbol may retrieve word variants: (((("_ decolonization across") or ("africa colonization failed"))) or ("its cooperation history"))*.