Perhaps you should try some spelling variations:
among patients » among nations
patients risk » patient risk, patients links, patients si
among east » among breast, among ers, among health
wang yang » wang yan, wang liang, wang yanling
yang yang » wang yan
yang jun » yang jui, pang jun, yang jin

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 yang ((yang jun) OR (yang yang)) among patients risk among east ;~.
• Adding a wildcard symbol may retrieve word variants: wang yang ((yang jun) or (yang yang)) among patients risk among east ;*.