Perhaps you should try some spelling variations:
present challenges » current challenges, assessment challenges
a present » _ present, 3 present, 2 present
wang yang » wang yan, wang liang, wang yanling
wong yue » wang yue, hong yu
min hong » amin hong, min hyoung, min jeong
tin hong » tan hong, kia hong, thi hong
yang xi » yang di, yang yi, yang jui
yue a » yu a, yue _

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 yang) OR (yang xi))wong yue a present challenges ((min hong) OR (tin hong)) hai ;~.
• Adding a wildcard symbol may retrieve word variants: ((wang yang) or (yang xi))wong yue a present challenges ((min hong) or (tin hong)) hai ;*.