Perhaps you should try some spelling variations:
human gene » human genome, human gender, human bone
zhang rong » zheng rong, zhang hong, zhang ming
van zhang » yan zhang, bin zhang, hao zhang
hua gene » hua ren, hy5 gene
using a » using _
rong yu » hong yu, rong su, wong yue
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: done ((using tax) OR (using a)) ((((hua gene) or (a gene))) or (human gene)) van zhang rong yu ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: done ((using tax) OR (using a)) ((((hua gene) OR (a gene))) OR (human gene)) van zhang rong yu ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "done ((using tax) OR (using a)) ((((hua gene) or (a gene))) or (human gene)) van zhang rong yu ;*".