Perhaps you should try some spelling variations:
challenges regarding » challenges remain, challenges facing, challenges during
treatment challenges » greatest challenges, present challenges, recent challenges
regarding zhong » regarding who
3 treatment » 4 treatment, 3.1 treatment, 5.3 treatment
zhong zhi » zhang zhi, hong ghi, zhong tai
nan yan » nan ya, wang yan, qian yan
yang xi » yang di, yang yi, yang jui
ya 3 » a 3, 2a 3, 4a 3

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: ((nan yan) OR (yang xi))ng ya 3 treatment challenges regarding zhong zhi ;~.
• Adding a wildcard symbol may retrieve word variants: ((nan yan) or (yang xi))ng ya 3 treatment challenges regarding zhong zhi ;*.