Perhaps you should try some spelling variations:
past case » east case, past based, test case
yang yang » wang yang, wang yan
shang kai » shang hai
wei shen » kwei sheng, enwei shen, wei shang
ying jin » yang jin, jing ji, yang jie
yang jui » yang judy, yang xi, yang yi
zhen » zheng, when, chen

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: past case zhen wei shen ((((((yang yang) OR (ying jin))) OR (yang di))) OR (yang jui)) shang kai ;~.
• Adding a wildcard symbol may retrieve word variants: past case zhen wei shen ((((((yang yang) or (ying jin))) or (yang di))) or (yang jui)) shang kai ;*.