Perhaps you should try some spelling variations:
yang yang » wang yang, wang yan
hua gene » human gene, hua ren, hy5 gene
wong sam » wong sau, wong lai, kong sar
yan yan » yan yuan, nan yan, wang yan
yang ji » yang jui, yang jie, yang jin
won sau » wong sau, wong siu
a gene » a genre, a gender, a gentle

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

• Performing a fuzzy search may retrieve terms with similar spellings: wan ((yan yan) OR (yang yang)) ((hua gene) or (a gene)) yang ji ((won sau) or (wong sam)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wan ((yan yan) OR (yang yang)) ((hua gene) OR (a gene)) yang ji ((won sau) OR (wong sam)) ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wan ((yan yan) OR (yang yang)) ((hua gene) or (a gene)) yang ji ((won sau) or (wong sam)) ;*".