Perhaps you should try some spelling variations:
cheng zhang » cheng han, zhen zhang, chen zheng
yuhan wang » yuan wang, yan wang, yuhuan huang
yuan cheng » yuan chang, huang cheng, yu cheng
chen zhang » zhen zhang, chen zheng, chen shuang
ping hong » ping pong, hong hong, tin hong
hong g » hong ng, hong w, hong 7

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: wang ((yuhan wang) or (yuan cheng)) hua ((chen zhang) OR (cheng zhang)) ping hong g ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang ((yuhan wang) OR (yuan cheng)) hua ((chen zhang) OR (cheng zhang)) ping hong g ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang ((yuhan wang) or (yuan cheng)) hua ((chen zhang) OR (cheng zhang)) ping hong g ;*".