Perhaps you should try some spelling variations:
"import trade integration theories." » "import trade integration theorems.", "import trade integrationstheorie 2.", "import trade integration theory.", "export trade integration theories.", "import taxes integration theories.", "import share integration theories."
"import price integrating policies." » "import price integration policies.", "import price integrated policies.", "import price integrating positive.", "import process integrating policies.", "import period integrating policies.", "import prices integrating policies.", "export price integrating policies.", "export prices integrating 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: (("import trade integration theories.") or ("import price integrating policies."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("import trade integration theories.") OR ("import price integrating policies.")).
• Removing quotes may allow a broader search: (( import trade integration theories. ) or ( import price integrating policies. )).
• Adding a wildcard symbol may retrieve word variants: (("import trade integration theories.") or ("import price integrating policies."))*.