Perhaps you should try some spelling variations:
patients risk » patient risk, patients links, patients si
risk along » risk among, ask along
hua jiang » ru jiang, nu jiang
along who » along two, wrong who
hua yang » hui yang, huang yang, apa yang
au costa » can costa, _ costa, da costa
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) OR (hua jiang)) ((a (cost or costs)) or (au costa)) patients risk along who ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang ((hua yang) OR (hua jiang)) ((a (cost OR costs)) OR (au costa)) patients risk along who ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang ((hua yang) OR (hua jiang)) ((a (cost or costs)) or (au costa)) patients risk along who ;*".