Perhaps you should try some spelling variations:
yang guang » yang yang, yan guan, yang liang
wai yang » wai yan, wei yang, wang yang
hua gene » human gene, a gene, hua ren
tang kia » tang li, kang kim, pang kin
yu chen » yu cheng, yulu chen, jui chen
yi chen » jui chen
hong yu » wong yue

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

• If you are trying to use Boolean operators, they must be ALL CAPS: wai yang guang ((hua gene) OR (((yu chen) OR (yi chen)))) tang kia hong yu ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wai yang guang ((hua gene) or (((yu chen) OR (yi chen)))) tang kia hong yu ;~".
• Adding a wildcard symbol may retrieve word variants: wai yang guang ((hua gene) or (((yu chen) OR (yi chen)))) tang kia hong yu ;*.