Perhaps you should try some spelling variations:
ratings risk » patients risk
can close » can lose, a close, can cause
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 lost » can lose, can post, can boost
can cost » can costa, can post, chain cost

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 lost) OR (can close))) OR (can cost)) ratings risk among ers ;~.
• Adding a wildcard symbol may retrieve word variants: wang dan yang ((((can lost) or (can close))) or (can cost)) ratings risk among ers ;*.