Perhaps you should try some spelling variations:
"pro colonization failed" » "pro colonization still", "pro organizations failed", "bio colonization failed", "re colonization failed", "mars colonization failed"
"pro decolonization case" » "pro decolonization across", "pro decolonization notes", "pro decolonization _", "_ decolonization case", "box decolonization case", "war decolonization case"
"city cooperation state" » "city cooperation scale", "city operation state", "city cooperation strategy", "city corporation state", "china cooperation state", "city corporations state"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("city cooperation state") or ("pro decolonization case"))) or ("pro colonization failed"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("city cooperation state") OR ("pro decolonization case"))) OR ("pro colonization failed")).
• Removing quotes may allow a broader search: (((( city cooperation state ) or ( pro decolonization case ))) or ( pro colonization failed )).
• Adding a wildcard symbol may retrieve word variants: (((("city cooperation state") or ("pro decolonization case"))) or ("pro colonization failed"))*.