Perhaps you should try some spelling variations:
"support key integration schemes." » "support key integration schengen.", "support key irrigation schemes.", "support key integration regimes.", "support der integration schemes.", "support de integration schemes.", "support 2e integration schemes.", "support deep integration schemes."
"support urban integration theory." » "support urban integration through.", "support urban information theory.", "support urban innovation theory.", "support european integration theory.", "support urban migration theory.", "support chain integration theory.", "support carbon integration theory.", "report urban integration theory.", "supply urban integration theory."

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

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