Perhaps you should try some spelling variations:
"import price integration theory." » "import price integration through.", "import price information theory.", "import price innovation theory.", "import service integration theory.", "import trade integration theory.", "import price indexation theory.", "import prices integration theory.", "export price integration theory.", "export prices integration theory."
"export policies meeting services." » "export policies being services.", "export policies dealing services.", "export policies sealing services.", "export policies testing services.", "export policies heating services.", "export policies marketing services.", "import policies meeting services.", "support policies meeting services.", "efforts policies meeting 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: (("import price integration theory.") or ("export policies meeting services."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("import price integration theory.") OR ("export policies meeting services.")).
• Removing quotes may allow a broader search: (( import price integration theory. ) or ( export policies meeting services. )).
• Adding a wildcard symbol may retrieve word variants: (("import price integration theory.") or ("export policies meeting services."))*.