Perhaps you should try some spelling variations:
"support eu integration theories." » "support eu integration theory.", "support eu integration through.", "support eu integration efforts.", "support _ integration theories.", "support deep integration theories.", "support data integration theories.", "support key integration theories.", "support a integration theories."
"import duty integration some." » "import data integration some.", "import south integration some.", "import deep integration some.", "import duty integration volume.", "import duty integration power.", "import duty integration south.", "import duties integration some."

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

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