Perhaps you should try some spelling variations:
yang cindy » yang mind
dong yang » dong hoang, wang yang, yang yang
yang yao » yang yang, wang yan, yang yi
than bau » than bad, than a, than you
can data » can tata, dan data, fan data
how hai » how has, how hci, how have
how ai » how aid, how ae, how am

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: dong yang yao ((than bau) OR (can data)) yang cindy ((how hai) OR (how ai)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "dong yang yao ((than bau) or (can data)) yang cindy ((how hai) OR (how ai)) ;~".
• Adding a wildcard symbol may retrieve word variants: dong yang yao ((than bau) or (can data)) yang cindy ((how hai) OR (how ai)) ;*.