Perhaps you should try some spelling variations:
teaching based » teaching case, teaching cases, teaching aid
based coping » based cropping, based costing, based scoring
hua credit » dual credit, du credit, ida credit
coping shu » cong shu
a credit » bad credit
sin a » sin _, win a, min a
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 a ((hua credit) OR (a credit)) teaching based coping shu ;~.
• Adding a wildcard symbol may retrieve word variants: dong sin a ((hua credit) or (a credit)) teaching based coping shu ;*.