Perhaps you should try some spelling variations:
douglas john » douglas jones, douglas j, douglas o
douglas bin » douglas b, douglas mair
bin zhang » binh thang, li zhang, jia zhang
yang zeng » yang erzeng, tang zheng, wang zheng
yu cheng » yu chen, _ cheng
rong tan » hong tan, rona tas, wing tan
tan yang » dan yang, tan ying, tan yong

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: zhang ((bin zhang) OR (yu cheng)) rong tan yang zeng ((douglas bin) OR (douglas john)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "zhang ((bin zhang) or (yu cheng)) rong tan yang zeng ((douglas bin) OR (douglas john)) ;~".
• Adding a wildcard symbol may retrieve word variants: zhang ((bin zhang) or (yu cheng)) rong tan yang zeng ((douglas bin) OR (douglas john)) ;*.