Perhaps you should try some spelling variations:
zhang zhang » zhen zhang, cheng zhang, zhang fang
costs using » tests using, costs arising, costs missing
wang liang » wang yang
using risk » during risk, using rs, funding risk
risk cong » risk coping, risk among, risk along
ying hua » ming hua, wang hua, ying zhu
using eu » using e, using ed, using es

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: ((wang liang) OR (zhang zhang)) ((ying hua) OR (using eu)) costs using risk cong shu ;~.
• Adding a wildcard symbol may retrieve word variants: ((wang liang) or (zhang zhang)) ((ying hua) or (using eu)) costs using risk cong shu ;*.