Perhaps you should try some spelling variations:
patients risk » patient risk, patients links, patients si
liang yang » liang ying, yang yang, huang yang
wang yang » wang yan, wang liang, wang yanling
risk hong » risk among, risk along, risk how
hong shu » cong shu, tong shui, wong shiu
eu cost » au costa, der cost, end cost

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 yang) or (wang yang)) ((eu cost) or (a cost)) patients risk hong shu ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang ((liang yang) OR (wang yang)) ((eu cost) OR (a cost)) patients risk hong shu ;.
• Adding a wildcard symbol may retrieve word variants: wang ((liang yang) or (wang yang)) ((eu cost) or (a cost)) patients risk hong shu ;*.