Perhaps you should try some spelling variations:
"supply trade integrationstheorie 2." » "supply der integrationstheorie 2.", "supply eine integrationstheorie 2.", "supply traditionelle integrationstheorie 2.", "supply trade integrationstheorie fur.", "supply trade integration theories.", "supply trade interpretationstheorie 2.", "supply case integrationstheorie 2."
"supply chain immigration policies." » "supply chain immigration policy.", "supply chain migration policy.", "supply chain migration policies.", "supply chain integration policies.", "supply chinese immigration 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: (("supply chain immigration policies.") or ("supply trade integrationstheorie 2."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply chain immigration policies.") OR ("supply trade integrationstheorie 2.")).
• Removing quotes may allow a broader search: (( supply chain immigration policies. ) or ( supply trade integrationstheorie 2. )).
• Adding a wildcard symbol may retrieve word variants: (("supply chain immigration policies.") or ("supply trade integrationstheorie 2."))*.