Perhaps you should try some spelling variations:
ratings risk » patients risk
among peers » among ers, among users, among letters
wang yang » wang yan, wang liang, wang yanling
yang ying » yang yang, yang jing, huang ying
can close » can lose, a close, can cause
can lost » can cost, can lose, 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 yang ying ((can close) or (can lost)) ratings risk among peers ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yang ying ((can close) OR (can lost)) ratings risk among peers ;*.