Perhaps you should try some spelling variations:
cleft patients » select patients, les patients, benefit patients
patients risk » patient risk, patients links, patients si
liang yang » liang ying, wang yang, huang yang
yang yang » wang yang, wang yan
den cleft » den client
among ers » among peers, among users, among east

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 (yang yang)) den cleft patients risk among ers ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang ((liang yang) OR (yang yang)) den cleft patients risk among ers ;*.