Perhaps you should try some spelling variations:
during risk » using risk, during crises, during crisis
risk coping » risk pooling
wang zhang » wang zheng, wang luhang, zhang zhang
zhang ming » zhang xin
coping shu » cong shu
au costa » can costa, _ costa, da costa
can cost » can costa, can lost, can post
der cost » oder cost, user cost, debt cost

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 zhang ming ((((au costa) OR (can cost))) OR (der cost)) during risk coping shu ;~.
• Adding a wildcard symbol may retrieve word variants: wang zhang ming ((((au costa) or (can cost))) or (der cost)) during risk coping shu ;*.