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

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