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 reach immigration policy." » "supply reach migration policy.", "supply race immigration policy.", "supply mass immigration policy.", "supply legal immigration policy.", "supply research immigration policy.", "supply great immigration policy.", "supply ch immigration policy."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("supply reach immigration policy.") or ("support grant integration theories."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply reach immigration policy.") OR ("support grant integration theories."))*.
• Removing quotes may allow a broader search: (( supply reach immigration policy. ) or ( support grant integration theories. ))*.