Perhaps you should try some spelling variations:
ghana health » china health, data health
health gain » health goals
young males » young ages
zhang yan » zhang fan, zhang jian, wang yan
sang minh » kang minah, anh minh, song min
chan ming » kian ming, chan eng, chan fong
wang » wing, lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((wang OR wan) yan) or (zhang yan)) ghana health gain ((sang minh) or (chan ming)) young males ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((wang OR wan) yan) OR (zhang yan)) ghana health gain ((sang minh) OR (chan ming)) young males ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((wang OR wan) yan) or (zhang yan)) ghana health gain ((sang minh) or (chan ming)) young males ;".
• Adding a wildcard symbol may retrieve word variants: (((wang OR wan) yan) or (zhang yan)) ghana health gain ((sang minh) or (chan ming)) young males ;*.