Perhaps you should try some spelling variations:
ratings risk » patients risk
wang yang » wang yan, wang liang, wang yanling
yang ying » yang yang, yang jing, huang ying
jun cost » run cost, eu cost
can cost » can costa, can lost, chain cost
can post » can lost, can past, can postal
how shu » how she, how shih, how slum

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang yang ying ((((jun cost) or (can cost))) or (can post)) ratings risk how shu ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yang ying ((((jun cost) OR (can cost))) OR (can post)) ratings risk how shu ;.
• Adding a wildcard symbol may retrieve word variants: wang yang ying ((((jun cost) or (can cost))) or (can post)) ratings risk how shu ;*.