Perhaps you should try some spelling variations:
ghana health » china health, data health
health gain » health goals
yang ghana » yang guang, change ghana
yang cindy » yang mind
wang yang » wang yan, wang liang, wang yanling
yang jin » yang jun, ying jin, shang jin
yang jie » yang di, yang jui, yang xi
tan » than

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 ghana health gain ((yang cindy) OR (((yang jin) OR (yang jie)))) hong tan ;~.
• Adding a wildcard symbol may retrieve word variants: wang yang ghana health gain ((yang cindy) or (((yang jin) or (yang jie)))) hong tan ;*.