Perhaps you should try some spelling variations:
dong yang » dong hoang, wang yang, yang yang
dong cao » dong xiao, dan cao, dong nan
a parent » _ parent, a patent, a patient
long du » long d, long do, long run
a bau » a bad, a bab, a ban
ya a » y a, ye a, yu a
a au » a auf, a aus, a u
a a » a la

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 cao) OR (dong yang)) ya a parent ((((a au) OR (a a))) OR (a bau)) long du ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((dong cao) or (dong yang)) ya a parent ((((a au) OR (a a))) or (a bau)) long du ;~".
• Adding a wildcard symbol may retrieve word variants: ((dong cao) or (dong yang)) ya a parent ((((a au) OR (a a))) or (a bau)) long du ;*.