Perhaps you should try some spelling variations:
"support migrant integration theories." » "support migrant integration theory.", "support migrant integration through.", "support migrant integration efforts.", "support market integration theories.", "support grant integration theories."
"support china integrating culture." » "support china integration culture.", "support china integrated culture.", "support count integrating culture.", "support china's integrating culture.", "report china integrating culture."

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