Perhaps you should try some spelling variations:
cleft patients » select patients, les patients, benefit patients
patients risk » patient risk, patients links, patients si
wing yanling » wang yanling, wang yangming
risk tong » risk among, risk along
yang jui » yang judy, yang di, yang xi
tong hui » wang hui
yang up » tying up, yang jun, hang ups

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: wing yanling ((yang up) OR (yang jui)) cleft patients risk tong hui ;~.
• Adding a wildcard symbol may retrieve word variants: wing yanling ((yang up) or (yang jui)) cleft patients risk tong hui ;*.