Perhaps you should try some spelling variations:
"supply china immigration policies." » "supply china immigration policy.", "supply china migration policy.", "supply china integration policies.", "supply child migration policies.", "supply national immigration policies.", "supply chains immigration policies.", "supply chain immigration policies."
"supply grid integration theories." » "supply grid integration theory.", "supply grid integration through.", "supply grid integration efforts.", "supply trade integration theories.", "supply _ integration theories.", "supply data integration theories.", "supply crowd integration theories.", "support grid integration theories."

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