Perhaps you should try some spelling variations:
"import prices integration theories." » "import prices integration theorems.", "import prices integrationstheorie 2.", "import prices integration theory.", "import price integration theories.", "import process integration theories.", "import policies integration theories.", "input prices integration theories."
"efforts policies hunting services." » "effects policies hunting services.", "export policies hunting services.", "forms policies hunting services.", "efforts policies changing services.", "efforts policies shifting services.", "efforts policies during services.", "efforts policies funding services.", "efforts policies heating services.", "efforts policies putting services."

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

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