Perhaps you should try some spelling variations:
"export prices integration theories." » "export prices integration theorems.", "export prices integrationstheorie 2.", "export prices integration theory.", "export price integration theories.", "export process integration theories.", "export policies integration theories.", "import 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: (("export prices integration theories.") OR ("efforts policies hunting services."))~.
• Removing quotes may allow a broader search: (( export prices integration theories. ) or ( efforts policies hunting services. ))~.
• Adding a wildcard symbol may retrieve word variants: (("export prices integration theories.") or ("efforts policies hunting services."))*.