Perhaps you should try some spelling variations:
credit training » credit trading, credit rationing, credit rating
training value » trading value, trading values
dual credit » rural credit, equal credit, rural credits
value cong » value co
wang yang » wang yan, wang liang, wang yanling
a dual » _ dual

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((dong or done) sin) or (wang yang)) a dual credit training value cong shu ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((dong OR done) sin) OR (wang yang)) a dual credit training value cong shu ;*.