Perhaps you should try some spelling variations:
yanling yang » yang yang, ying yang
ratings risk » patients risk
patient risk » patients risk, patient task, patient cost
yan yanling » wang yanling, yan jianping
yang lost » can lost
among who » along who, among hr, wrong who
wang » wing, wan, lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang yan yanling yang lost ((ratings risk) or (patient risk)) among who ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yan yanling yang lost ((ratings risk) OR (patient risk)) among who ;*.