Perhaps you should try some spelling variations:
china health » china's health, child health, capita health
health gain » health goals
yang china » hang china, kong china, ming china
wang yang » wang yan, wang liang, wang yanling
yang mind » yang cindy, sang minh, tang min
yang jin » yang jie, yang jun, ying jin

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

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