Perhaps you should try some spelling variations:
"import data integration theories." » "import data integration theorems.", "import data integrationstheorie 2.", "import data integration theory.", "import data integrity theories.", "import duty integration theories."
"improve water integrating policies." » "improve water integration policies.", "improve water integrated policies.", "improve water integrating positive.", "improve lever integrating policies.", "improve patterns integrating policies.", "improving water integrating policies."

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 theories.") or ("improve water integrating policies."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("import data integration theories.") OR ("improve water integrating policies."))*.
• Removing quotes may allow a broader search: (( import data integration theories. ) or ( improve water integrating policies. ))*.