Perhaps you should try some spelling variations:
among lecturers » among letters
patients death » patients eat, patients search, patients near
death among » deaths among, health among
wang liang » wang yang
yang yang » wang yang, wang yan
yang can » yang 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 can) or (yang yang)) cancer patients death among lecturers ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang liang ((yang can) OR (yang yang)) cancer patients death among lecturers ;*.