Perhaps you should try some spelling variations:
"support a integration theories." » "support a integration theorems.", "support a integrationstheorie 2.", "support a integration theory.", "support 3 integration theories.", "support 2 integration theories.", "support 4 integration theories.", "support _ integration theories."
"support mass immigration policies." » "support mass immigration policy.", "support mass migration policy.", "support mass migration policies.", "support _ immigration policies.", "support mcfs immigration policies.", "support mdbs immigration policies.", "support basic immigration policies."

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: (("support a integration theories.") or ("support mass immigration policies."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("support a integration theories.") OR ("support mass immigration policies.")).
• Removing quotes may allow a broader search: (( support a integration theories. ) or ( support mass immigration policies. )).
• Adding a wildcard symbol may retrieve word variants: (("support a integration theories.") or ("support mass immigration policies."))*.