Perhaps you should try some spelling variations:
ratings risk » patients risk
risk along » risk among, ask along
along who » along two, wrong who
hua yang » hui yang, huang yang, hua jiang
hua cost » a 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 (eu cost)) ratings risk along who ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang hua yang ((hua cost) OR (eu cost)) ratings risk along who ;*".