Perhaps you should try some spelling variations:
"support social integration theories." » "support social integration theorems.", "support social integrationstheorie 2.", "support social integration theory.", "support global integration theories.", "support financial integration theories.", "support regional integration theories.", "supporting social integration theories.", "supply social integration theories."
"export trade integrating services." » "export trade integration services.", "export trade integrated services.", "export trade regulating services.", "export true integrating services.", "export drama integrating services.", "export taxes integrating services.", "export base integrating services.", "export tax integrating services."

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