Perhaps you should try some spelling variations:
"supply chain integration theories." » "supply chain integration theorems.", "supply chain integrationstheorie 2.", "supply chain integration theory."
"support migrants integration series." » "support migrant integration series.", "support immigrants integration series.", "support migrants l'integration series.", "support migrants integration services.", "support migrants interaction series.", "support migrants integration server.", "supporting migrants integration series.", "support grant integration series."

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: (("supply chain integration theories.") OR ("support migrants integration series."))~.
• Removing quotes may allow a broader search: (( supply chain integration theories. ) or ( support migrants integration series. ))~.
• Adding a wildcard symbol may retrieve word variants: (("supply chain integration theories.") or ("support migrants integration series."))*.