Perhaps you should try some spelling variations:
"support trade integration theories." » "support trade integration theory.", "support trade integration through.", "support trade integration efforts.", "export trade integration theories.", "support grant integration theories.", "import trade integration theories."
"support social integration series." » "support global integration series.", "support financial integration series.", "support regional integration series.", "support social integrating services.", "support social integration schemes.", "support social integration social.", "supporting social integration series.", "supply social integration series."

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