Perhaps you should try some spelling variations:
"support key integration theories." » "support key integration theory.", "support key integration through.", "support key integration efforts.", "support eu integration theories.", "support deep integration theories.", "support _ integration theories.", "support them integration theories.", "support does integration theories."
"import data integration schemes." » "import data irrigation schemes.", "import data integration some.", "import trade integration schemes.", "import _ integration schemes.", "import data integrity schemes.", "import duty integration schemes."

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

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