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

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))ong ye a present challenges ((min hong) OR (tin hong)) hai ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang yang) or (yang xi))ong ye a present challenges ((min hong) OR (tin hong)) hai ;~".
• Adding a wildcard symbol may retrieve word variants: ((wang yang) or (yang xi))ong ye a present challenges ((min hong) OR (tin hong)) hai ;*.