Perhaps you should try some spelling variations:
wang luhang » wang liang, wang lihong, wang yuhan
zhang zhang » zhen zhang, cheng zhang, zhang fang
cost during » boost during, crust during, west during
during risk » using risk, during crises, during crisis
risk coping » risk pooling
coping shu » cong shu
using eu » using e, using ed, using es
ying eu » ying zhu, ying hua

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 luhang) OR (zhang zhang)) ((ying eu) OR (using eu)) cost during risk coping shu ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang luhang) or (zhang zhang)) ((ying eu) OR (using eu)) cost during risk coping shu ;~".
• Adding a wildcard symbol may retrieve word variants: ((wang luhang) or (zhang zhang)) ((ying eu) OR (using eu)) cost during risk coping shu ;*.