Perhaps you should try some spelling variations:
ratings risk » patients risk
wang liang » wang yang
liang yang » liang ying, wang yang, yang yang
life cost » life costs, life lost, life case
diet cost » die cost, direct cost, net cost
jie cost » die cost, time cost, side cost
among eu » among men, among _, among 15

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 liang yang ((((jie cost) OR (life cost))) OR (diet cost)) ratings risk among eu ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang liang yang ((((jie cost) OR (life cost))) or (diet cost)) ratings risk among eu ;~".
• Adding a wildcard symbol may retrieve word variants: wang liang yang ((((jie cost) OR (life cost))) or (diet cost)) ratings risk among eu ;*.