Perhaps you should try some spelling variations:
"supply water integration schemes." » "supply water integration schengen.", "supply water irrigation schemes.", "supply water integration regimes.", "supply water integrating schemes.", "supply factor integration schemes.", "supply filter integration schemes."
"import duty integration theory." » "import duty integration through.", "import duty information theory.", "import duty innovation theory.", "import dutch integration theory.", "import data integration theory.", "import why integration theory.", "import duties integration theory."

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: (("supply water integration schemes.") OR ("import duty integration theory."))~.
• Removing quotes may allow a broader search: (( supply water integration schemes. ) or ( import duty integration theory. ))~.
• Adding a wildcard symbol may retrieve word variants: (("supply water integration schemes.") or ("import duty integration theory."))*.