Perhaps you should try some spelling variations:
credit rationing » credit rating, credit ratings
credit trading » credit training, credit rating, credit standing
value cong » value co, value closing, value change
wang yong » wang yang, wang hyoung, wang yan
a dual » _ dual
dong » doing, long, done

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 sin) OR (wang yong)) a dual ((credit trading) OR (credit rationing)) value cong shu ;~.
• Adding a wildcard symbol may retrieve word variants: ((dong sin) or (wang yong)) a dual ((credit trading) or (credit rationing)) value cong shu ;*.