Perhaps you should try some spelling variations:
among african » among africans, among american, among mexican
hua gene » human gene, a gene, hua ren
yang lin » wang lin, yang li, yang liang
yang jin » yang jie, yang jun, ying jin
zong shu » cong shu, tong shui, wong shiu
dong di » dong sin
jing ji » 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: ((dong di) or (among african)) ya hua gene ((yang lin) or (((yang jin) or (jing ji)))) zong shu ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((dong di) OR (among african)) ya hua gene ((yang lin) OR (((yang jin) OR (jing ji)))) zong shu ;.
• Adding a wildcard symbol may retrieve word variants: ((dong di) or (among african)) ya hua gene ((yang lin) or (((yang jin) or (jing ji)))) zong shu ;*.