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 series." » "support grid integrating services.", "support grid integration schemes.", "support grid integration social.", "support trade integration series.", "support _ integration series.", "support agri integration series.", "support grant integration series.", "support group integration series."

Try widening your search to All Fields.

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