Perhaps you should try some spelling variations:
treatment challenges » greatest challenges, present challenges, recent challenges
challenges funding » challenges finding, challenge finding, challenges branding
funding among » bonding among, building among, jumping among
among zhi » among di, among hiv, among hr
nan yan » nan ya, wang yan, qian yan
yang xi » yang di, yang yi, yang jui
ya 3 » a 3, 4a 3, 5a 3
2a 3 » 2 3, a 3, 20 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) OR (2a 3)) treatment challenges funding among zhi ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((nan yan) or (yang xi))ng ((ya 3) OR (2a 3)) treatment challenges funding among zhi ;~".
• Adding a wildcard symbol may retrieve word variants: ((nan yan) or (yang xi))ng ((ya 3) OR (2a 3)) treatment challenges funding among zhi ;*.