Perhaps you should try some spelling variations:
ratings risk » patients risk
among ers » among peers, among users, among east
wang dan » wang yan, wang ban, wang yidan
dan yang » daun yang, tan yang, wang yang
can post » can past, can postal, can boost
can lost » can lose, can boost, can close
can cost » can costa, chain cost, can boost

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

• If you are trying to use Boolean operators, they must be ALL CAPS: wang dan yang ((((can post) OR (can lost))) OR (can cost)) ratings risk among ers ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang dan yang ((((can post) OR (can lost))) or (can cost)) ratings risk among ers ;~".
• Adding a wildcard symbol may retrieve word variants: wang dan yang ((((can post) OR (can lost))) or (can cost)) ratings risk among ers ;*.