Perhaps you should try some spelling variations:
"re decolonization africa" » "re democratization africa", "_ decolonization africa", "re colonization africa", "box decolonization africa"
"_ colonization history" » "_ communication history", "_ organization history", "_ civilization history", "_ decolonization history", "decolonization _ history"
"de cooperation history" » "de corporation history", "de federation history", "2 cooperation history", "trade cooperation history", "area 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: (((("re decolonization africa") OR ("_ colonization history"))) OR ("de cooperation history"))~.
• Removing quotes may allow a broader search: (((( re decolonization africa ) or ( _ colonization history ))) or ( de cooperation history ))~.
• Adding a wildcard symbol may retrieve word variants: (((("re decolonization africa") or ("_ colonization history"))) or ("de cooperation history"))*.