Perhaps you should try some spelling variations:
ratings risk » patients risk
risk wrong » risk among, risk along
wrong when » wrong keen, wrong what, wrong who
hua yang » hui yang, huang yang, hua jiang
hua cost » run cost
eu cost » au costa, der cost, end cost
wang » wing, wan, lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang hua yang ((((hua cost) OR (a cost))) or (eu cost)) ratings risk wrong when ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang hua yang ((((hua cost) OR (a cost))) OR (eu cost)) ratings risk wrong when ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang hua yang ((((hua cost) OR (a cost))) or (eu cost)) ratings risk wrong when ;*".