Perhaps you should try some spelling variations:
cleft patients » select patients, les patients, benefit patients
close patients » care patients, les patients, obese patients
among learners » among farmers, among teachers, among learning
wang liang » wang yang
yang yang » wang yang, wang yan
eat among » death among, dead among, test among
yang fan » zhang fan, yang dean, yang jin

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 fan) or (yang yang)) ((close patients) OR (cleft patients)) eat among learners ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang liang ((yang fan) OR (yang yang)) ((close patients) OR (cleft patients)) eat among learners ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang liang ((yang fan) or (yang yang)) ((close patients) OR (cleft patients)) eat among learners ;*".