Perhaps you should try some spelling variations:
patients death » patients eat, patients search, patients near
among letters » among lecturers, among learners, among masters
death among » deaths among, health among
wang liang » wang yang
yang yang » wang yang, wang yan
yang can » yang dean, yang jin, yang jun
yang fan » zhang fan, yang dean, yang jin

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: wang liang ((((yang can) OR (yang fan))) OR (yang yang)) cancer patients death among letters ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang liang ((((yang can) OR (yang fan))) or (yang yang)) cancer patients death among letters ;~".
• Adding a wildcard symbol may retrieve word variants: wang liang ((((yang can) OR (yang fan))) or (yang yang)) cancer patients death among letters ;*.