Perhaps you should try some spelling variations:
douglas john » douglas jones, douglas j, douglas o
things zeng » things zhang, things end, things using
douglas b » douglas f, douglas w, douglas a
yang yun » yang jun, tang yun, yang yue
yang jin » yang jie, yang jun, ying jin
li first » ai first, i first, ii first

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 ((yang yun) OR (yang jin)) li first things zeng ((douglas b) OR (douglas john)) ;~.
• Adding a wildcard symbol may retrieve word variants: wang ((yang yun) or (yang jin)) li first things zeng ((douglas b) or (douglas john)) ;*.