Perhaps you should try some spelling variations:
human gender » bhutan gender, human gene, german gender
yang liang » wang liang, yan liang, yang yang
zhong tai » hong tan, hong hai, zhong zhi
hua chen » jui chen, yu chen, a chen
yang jin » yang jie, yang jun, ying jin
yan xi » yang xi, yan zi
wang » wing, lang

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: (wang OR wan) yan xi ((hua chen) OR (human gender)) ((yang liang) OR (yang jin)) zhong tai ;~.
• Adding a wildcard symbol may retrieve word variants: (wang or wan) yan xi ((hua chen) or (human gender)) ((yang liang) or (yang jin)) zhong tai ;*.