Perhaps you should try some spelling variations:
select patients » cleft patients, selecting patient, benefit patients
patients risk » patient risk, patients links, patients si
wang yang » wang yan, wang liang, wang yanling
risk tong » risk among, risk along
tong shui » tong hui, cong shu, gong hui
tying up » taking up, tying _
pang jun » yang jui

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang yang ((tying up) or (pang jun)) select patients risk tong shui ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yang ((tying up) OR (pang jun)) select patients risk tong shui ;.
• Adding a wildcard symbol may retrieve word variants: wang yang ((tying up) or (pang jun)) select patients risk tong shui ;*.