Perhaps you should try some spelling variations:
patients risk » patient risk, patients links, patients si
risk along » risk among, ask along
along who » along two, wrong who
wang wei » zhang wei, wang zhi
wei yang » pei yang, wei wang, wei yang's
hua cost » a cost, eu cost, run cost
au costa » can costa, _ costa, da costa

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang wei yang ((hua cost) or (au costa)) patients risk along who ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang wei yang ((hua cost) OR (au costa)) patients risk along who ;*.