Perhaps you should try some spelling variations:
"support net immigration policies." » "support net immigration policy.", "support net migration policy.", "support net migration policies.", "support anti immigration policies.", "support _ immigration policies.", "support new immigration policies.", "support de immigration policies.", "support act immigration policies."
"support data irrigation schemes." » "support data irrigation scheme.", "support data irrigation systems.", "support delta irrigation schemes.", "support canal irrigation schemes.", "support water irrigation schemes.", "support a irrigation schemes.", "support de irrigation schemes."

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

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