Perhaps you should try some spelling variations:
"supply cost immigration policies." » "supply cost immigration policy.", "supply cost migration policy.", "supply gross immigration policies.", "supply first immigration policies.", "supply mass immigration policies.", "supply costs immigration policies."
"supply countries developing policies." » "supply countries development policies.", "supply countries develop policies.", "supply industries developing policies.", "supply countries developing policy.", "supply countries developing societies.", "supplier countries developing policies.", "small countries developing policies.", "supply curves developing policies."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("supply cost immigration policies.") or ("supply countries developing policies."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply cost immigration policies.") OR ("supply countries developing policies.")).
• Removing quotes may allow a broader search: (( supply cost immigration policies. ) or ( supply countries developing policies. )).
• Adding a wildcard symbol may retrieve word variants: (("supply cost immigration policies.") or ("supply countries developing policies."))*.