Perhaps you should try some spelling variations:
"support key integration theories." » "support key integration theorems.", "support key integrationstheorie 2.", "support key integration theory.", "support der integration theories.", "support de integration theories.", "support 2e integration theories.", "support deep integration theories."
"import trade integration south." » "import trade integration study.", "import trade integration some.", "import trade integration social.", "export trade integration south.", "import price integration south.", "import taxes integration south."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("import trade integration south.") or ("support key integration theories."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("import trade integration south.") OR ("support key integration theories.")).
• Removing quotes may allow a broader search: (( import trade integration south. ) or ( support key integration theories. )).
• Adding a wildcard symbol may retrieve word variants: (("import trade integration south.") or ("support key integration theories."))*.