Perhaps you should try some spelling variations:
present challenges » current challenges, assessment challenges
challenges m » challenges 1, challenges 3, challenges 5
wang yang » wang yan, wang liang, wang yanling
a present » _ present, 3 present, 2 present
hong hai » shang hai, zhong tai, hong tan
yang xi » yang di, yang yi, yang jui
ya a » a a, y a, ye a

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 xi))ng ya a present challenges m ((hong hai) OR (dang hai)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang yang) OR (yang xi))ng ya a present challenges m ((hong hai) OR (dang hai)) ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang yang) or (yang xi))ng ya a present challenges m ((hong hai) OR (dang hai)) ;".
• Adding a wildcard symbol may retrieve word variants: ((wang yang) or (yang xi))ng ya a present challenges m ((hong hai) OR (dang hai)) ;*.