Perhaps you should try some spelling variations:
yulan zhang » xiulan zhang, yan zhang, yuan chang
chen yulan » chen yugang, chen yulu, chen yun
zhang hong » zhang rong, change hong, zhang zhang
hong ng » hong kong, hong jong, hong hong
dong di » dong sin
hong du » hong yu, long du, hong tou
n chen » _ chen, a chen, z chen
y n » y en, y un
wang » wing, wan, lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((((wang yan) or (hong ng))) or (dong di)) y n chen yulan zhang hong du ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((wang yan) OR (hong ng))) OR (dong di)) y n chen yulan zhang hong du ;*.