Perhaps you should try some spelling variations:
cost ratings » cost savings, costs savings, bond ratings
ratings risk » patients risk
liang ying » liang liying, huang ying, zhang ying
yang yang » wang yang, wang yan
hua cost » a cost, eu cost, run cost
hong shu » tong shui, wong shiu, hong seo

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang ((liang ying) or (yang yang)) hua cost ratings risk ((hong shu) OR (cong shu)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang ((liang ying) OR (yang yang)) hua cost ratings risk ((hong shu) OR (cong shu)) ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang ((liang ying) or (yang yang)) hua cost ratings risk ((hong shu) OR (cong shu)) ;".
• Adding a wildcard symbol may retrieve word variants: wang ((liang ying) or (yang yang)) hua cost ratings risk ((hong shu) OR (cong shu)) ;*.