Perhaps you should try some spelling variations:
cost patients » cost patient, cleft patients, care patients
patients risk » patient risk, patients links, patients si
risk wrong » risk among, risk along
wrong when » wrong keen, wrong what, wrong who
wang wang » wang yang, wang liang, wang yan
wang yong » wang yang, wang yan, wang shiyong
oder cost » der cost, lower cost, power cost

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 wang) OR (((wang yong) OR (wang hyoung)))) yang oder cost patients risk wrong when ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang wang) or (((wang yong) OR (wang hyoung)))) yang oder cost patients risk wrong when ;~".
• Adding a wildcard symbol may retrieve word variants: ((wang wang) or (((wang yong) OR (wang hyoung)))) yang oder cost patients risk wrong when ;*.