Perhaps you should try some spelling variations:
"american colonial empires" » "american colonization empires", "american colonial empire"
"american colonies empire" » "american colonial empire", "american coloured empire", "american colonialism empire"

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: (("american colonial empires") OR ("american colonies empire")).
• Removing quotes may allow a broader search: (( american colonial empires ) or ( american colonies empire )).
• Adding a wildcard symbol may retrieve word variants: (("american colonial empires") or ("american colonies empire"))*.