Perhaps you should try some spelling variations:
ratings risk » patients risk
wang huang » wang luhang, wang hua, wang liang
huang ying » huang jing, huang ting, huang yang
among east » among breast, among ers, among health
hang lost » have lost, has lost, hang out
can lost » can cost, can lose, can post

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "wang huang ying ((hang lost) OR (can lost)) ratings risk among east ;~".
• Adding a wildcard symbol may retrieve word variants: wang huang ying ((hang lost) OR (can lost)) ratings risk among east ;*.