Perhaps you should try some spelling variations:
"support policy intervention series." » "support policy intervention prices.", "support policy intervention systems.", "support policy intervention design.", "support policy interventions series.", "support policies intervention series.", "import policy intervention series."
"import bans integration south." » "import bans integration study.", "import bans integration some.", "import bans integration through.", "import can integration south.", "import urban integration south.", "import data integration south.", "import taxes integration south."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("import bans integration south.") OR ("support policy intervention series."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"import bans integration south.\") OR (\"support policy intervention series.\"))*".
• Removing quotes may allow a broader search: (( import bans integration south. ) OR ( support policy intervention series. ))*.