Perhaps you should try some spelling variations:
ghana health » data health
china health » china's health, child health, capita health
hyoung tan » hyoung gun, young man
gain sang » shin sang, gain sharing
sang min » sang minh, song min, tang min
wang » wing, wan, lang
hong » long

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) or (china health)) gain sang min ((hyoung tan) OR (hong tan)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yan ((ghana health) OR (china health)) gain sang min ((hyoung tan) OR (hong tan)) ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang yan ((ghana health) or (china health)) gain sang min ((hyoung tan) OR (hong tan)) ;".
• Adding a wildcard symbol may retrieve word variants: wang yan ((ghana health) or (china health)) gain sang min ((hyoung tan) OR (hong tan)) ;*.