Perhaps you should try some spelling variations:
among african » among africans, among american, among mexican
human gene » human genome, human gender, human bone
gene yang » gene bank
wong shiu » wong siu, cong shu, song shin
tong hui » wang hui
dong di » dong sin
2 human » 3 human
yang li » yang lin, yang di, yang xi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((dong di) or (among african)) 2 human gene yang li ((tong hui) or (wong shiu)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((dong di) OR (among african)) 2 human gene yang li ((tong hui) OR (wong shiu)) ;.
• Adding a wildcard symbol may retrieve word variants: ((dong di) or (among african)) 2 human gene yang li ((tong hui) or (wong shiu)) ;*.