Perhaps you should try some spelling variations:
"supply mass immigration policies." » "supply mass immigration policy.", "supply mass migration policy.", "supply mass migration policies.", "supply _ immigration policies.", "supply case immigration policies.", "supply main immigration policies.", "supply many immigration policies."
"support a interaction series." » "support a interactions series.", "support a interaction studies.", "support a interaction terms.", "support ai interaction series.", "support 2 interaction series.", "support 3 interaction series.", "support _ interaction series."

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

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