Perhaps you should try some spelling variations:
"supply china migration policies." » "supply china immigration policies.", "supply china migration policy.", "supply china education policies.", "supply child migration policies.", "supply change migration policies.", "supply can migration policies.", "supply chains migration policies.", "supply chain migration policies."
"supply sector integration series." » "supply social integration series.", "supply sector integration theories.", "supply sector integrating services.", "supply sector integration schemes."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("supply china migration policies.") or ("supply sector integration series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply china migration policies.") OR ("supply sector integration series."))*.
• Removing quotes may allow a broader search: (( supply china migration policies. ) or ( supply sector integration series. ))*.