Perhaps you should try some spelling variations:
douglas mary » douglas mair, douglas a, douglas m
douglas bin » douglas b, douglas john, douglas mair
things zeng » things zhang, things end, things using
wang liang » wang yang
yang jui » yang judy, yang di, yang xi
yan guan » gan guan, yan yuan, yang guang

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 jui) OR (yan guan)) smart things zeng ((douglas bin) OR (douglas mary)) ;~.
• Adding a wildcard symbol may retrieve word variants: wang liang ((yang jui) or (yan guan)) smart things zeng ((douglas bin) or (douglas mary)) ;*.