Perhaps you should try some spelling variations:
ratings risk » patients risk
patient risk » patients risk, patient task, patient cost
wang liang » wang yang
liang yang » liang ying, wang yang, yang yang
among east » among breast, among ers
yang can » yang fan, yang dean, yang yang
can cost » can costa, can lost, can post

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

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