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 price integration theories.", "import taxes integration theories."
"export price integration through." » "export price innovation through.", "export service integration through.", "export price indexation through.", "export die integration through.", "export prices integration through.", "import prices integration through."

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