Perhaps you should try some spelling variations:
"import data integration theories." » "import data integration theory.", "import data integration through.", "import data integration efforts.", "import trade integration theories.", "import _ integration theories.", "import data integrity theories.", "import duty integration theories."
"support grid integration schemes." » "support grid irrigation schemes.", "support grid integration some.", "support trade integration schemes.", "support _ integration schemes.", "support agri integration schemes.", "support grant integration schemes.", "support group 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: (("support grid integration schemes.") or ("import data integration theories."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("support grid integration schemes.") OR ("import data integration theories.")).
• Removing quotes may allow a broader search: (( support grid integration schemes. ) or ( import data integration theories. )).
• Adding a wildcard symbol may retrieve word variants: (("support grid integration schemes.") or ("import data integration theories."))*.