Perhaps you should try some spelling variations:
cost learning » clt learning, ct learning, past learning
learning risk » learning crisis, learning r, learning rate
wang liang » wang yang
risk wrong » risk among, risk along
wrong who » wrong why, wrong what, wrong when
yang can » yang fan, yang dean, yang yang
can cost » can costa, can lost, can post

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((wang liang) OR (wang yan)) yang can cost learning risk wrong who ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang liang) OR (wang yan)) yang can cost learning risk wrong who ;*".