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."
"support group cooperation efforts." » "support group conservation efforts.", "support group cooperation forms.", "support group collection efforts.", "support group operations efforts.", "support global cooperation efforts.", "support gulf cooperation efforts.", "support grant cooperation efforts."

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

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