Perhaps you should try some spelling variations:
class dong » class doing, class do
dong since » dong sin
one class » one case
yang yang » wang yang, wang yan
since ce » since c, since _, since eu
gong min » jong min, song min, gong meng
yang jin » yang jie, yang jun, ying jin
yang yun » yang jun, tang yun, yang yue
yang yi » yang di, 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 dong since ce ((((gong min) OR (yang yang))) OR (yang jin)) ((yang yun) OR (yang yi)) ;~.
• Adding a wildcard symbol may retrieve word variants: one class dong since ce ((((gong min) or (yang yang))) or (yang jin)) ((yang yun) or (yang yi)) ;*.