Perhaps you should try some spelling variations:
challenges ma » challenges m, challenges 1, challenges 3
wang yang » wang yan, wang liang, wang yanling
1 current » 2 current, 3.1 current
3 current » 3 concurrent
shang hai » shang kai, dang hai, chang ha
ma shang » gao shang, xia shang, _ shang
ng y » ng _, g y, na y

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((wang yang) or (yang di))ng y ((1 current) OR (3 current)) challenges ma shang hai ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang yang) OR (yang di))ng y ((1 current) OR (3 current)) challenges ma shang hai ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang yang) or (yang di))ng y ((1 current) OR (3 current)) challenges ma shang hai ;".
• Adding a wildcard symbol may retrieve word variants: ((wang yang) or (yang di))ng y ((1 current) OR (3 current)) challenges ma shang hai ;*.