Perhaps you should try some spelling variations:
ratings risk » patients risk
cost ratings » cost savings, costs savings, bond ratings
wang yang » wang yan, wang liang, wang yanling
yang jun » yang jui, yang jin, yang judy
pang jun » yang jui
ying jin » yang jin, jing ji, yang jie
among 15 » among _, among eu

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 (pang jun))) OR (ying jin)) cost ratings risk among 15 ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang yang ((((yang jun) OR (pang jun))) or (ying jin)) cost ratings risk among 15 ;~".
• Adding a wildcard symbol may retrieve word variants: wang yang ((((yang jun) OR (pang jun))) or (ying jin)) cost ratings risk among 15 ;*.