Perhaps you should try some spelling variations:
"support grant integration theories." » "support grant integration theorems.", "support grant integrationstheorie 2.", "support grant integration theory.", "support migrant integration theories.", "support migrants integration theories.", "support statt integration theories."
"supply scale immigration policy." » "supply scale migration policy.", "supply scale irrigation policy.", "supply scale integration policy.", "supply case immigration policy.", "supply scheme immigration policy.", "supply social immigration policy."

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

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