Perhaps you should try some spelling variations:
cost patients » cost patient, cleft patients, des patients
care patients » cancer patients, failure patients
risk tong » risk among, risk along
tong shui » tong hui, cong shu, gong hui
tying up » taking up, tying _
yang jun » yang jui, pang jun, yang jin
wang » wing, wan, lang

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 yanling ((tying up) OR (yang jun)) ((cost patients) OR (care patients)) risk tong shui ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang yanling ((tying up) or (yang jun)) ((cost patients) OR (care patients)) risk tong shui ;~".
• Adding a wildcard symbol may retrieve word variants: wang yanling ((tying up) or (yang jun)) ((cost patients) OR (care patients)) risk tong shui ;*.