Perhaps you should try some spelling variations:
"support migrant integration theory." » "support market integration theory.", "support migrant integration through.", "support migrant information theory.", "support migrant innovation theory.", "support migrants integration theory.", "support grant integration theory.", "supporting migrants integration theory."
"support a integration series." » "support a integration services.", "support a interaction series.", "support a integration server.", "support 3 integration series.", "support 2 integration series.", "support 4 integration series.", "support _ integration series."

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

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