Perhaps you should try some spelling variations:
dong nana » dong nan, dong yang
yang yang » wang yan
wang yang » wang yan, wang liang, wang yanling
gene yang » gene bank
yala hua » ya hua
hua gene » human gene, a gene, hua ren
tan dang » tan yang, tang tang, tan kong

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((dong nana) or (((yang yang) or (wang yang)))) yala hua gene yang ((tan dang) OR (tan hong)) hai ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((dong nana) OR (((yang yang) OR (wang yang)))) yala hua gene yang ((tan dang) OR (tan hong)) hai ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((dong nana) or (((yang yang) or (wang yang)))) yala hua gene yang ((tan dang) OR (tan hong)) hai ;".
• Adding a wildcard symbol may retrieve word variants: ((dong nana) or (((yang yang) or (wang yang)))) yala hua gene yang ((tan dang) OR (tan hong)) hai ;*.