Perhaps you should try some spelling variations:
german gender » german lander, germany under, german border
human gender » bhutan gender, human gene, human genome
yuan cheng » yuan chang, huang cheng, yu cheng
cheng han » chen hao
yang chik » nong chik
wang chi » wang zhi, wang chau, wang chun
hong yu » wong yue

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

• Performing a fuzzy search may retrieve terms with similar spellings: yuan cheng han ((human gender) OR (german gender)) ((yang chik) or (wang chi)) hong yu ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: yuan cheng han ((human gender) OR (german gender)) ((yang chik) OR (wang chi)) hong yu ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "yuan cheng han ((human gender) OR (german gender)) ((yang chik) or (wang chi)) hong yu ;*".