Perhaps you should try some spelling variations:
class dann » class demand
one class » one case
dann doch » kann doch, dann auch, dann nich
doch chen » goh chen, don chen
dong ping » dong sin, dong bin, dong jung
wang yue » wong yue, wang hua, wang yan
jing ji » ying jin
yang yi » yang xi, yang jui

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: one class dann doch chen ((((jing ji) OR (dong ping))) OR (yang yi)) ((wang yue) OR (yang di)) ;~.
• Adding a wildcard symbol may retrieve word variants: one class dann doch chen ((((jing ji) or (dong ping))) or (yang yi)) ((wang yue) or (yang di)) ;*.