Perhaps you should try some spelling variations:
cleft patients » select patients, les patients, benefit patients
close patients » care patients, les patients, obese patients
among letters » among lecturers, among learners, among masters
wang liang » wang yang
liang yang » liang ying, wang yang, yang yang
yang can » yang fan, yang dean, yang yang

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 can ((close patients) OR (cleft patients)) risk among letters ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang liang yang can ((close patients) OR (cleft patients)) risk among letters ;*".