Perhaps you should try some spelling variations:
"class communication issues" » "class community issues", "class communication india", "class communication united", "mass communication issues", "plans communication issues", "crisis communication issues"
"re colonization failed" » "re colonization still", "re organizations failed", "pro colonization failed", "_ colonization failed", "jews colonization failed"
"city cooperation sources" » "city cooperation series", "city cooperation studies", "city cooperation countries", "city corporation sources", "china cooperation sources", "city corporations sources"

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: (("class communication issues") or ((("re colonization failed") or ("city cooperation sources"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("class communication issues") OR ((("re colonization failed") OR ("city cooperation sources")))).
• Removing quotes may allow a broader search: (( class communication issues ) or ((( re colonization failed ) or ( city cooperation sources )))).
• Adding a wildcard symbol may retrieve word variants: (("class communication issues") or ((("re colonization failed") or ("city cooperation sources"))))*.