Perhaps you should try some spelling variations:
ghana health » china health, data health
health gain » health goals
yan ghana » yan guan, yan zhang
tang min » chang min, sang minh, yang mind
yang jin » yang jie, yang jun, ying jin
wang » wing, wan, lang
tang » thang
tan » than

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: wang yan ghana health gain ((tang min) or (yang jin)) hong tan ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yan ghana health gain ((tang min) OR (yang jin)) hong tan ;.
• Adding a wildcard symbol may retrieve word variants: wang yan ghana health gain ((tang min) or (yang jin)) hong tan ;*.