Perhaps you should try some spelling variations:
german gender » german lander, germany under, german border
human gender » bhutan gender, human gene, human genome
yang yin » yang yi, yang jin, yang lin
yin yang » ying yang, yi yang, yin fang
yang min » yang mind, yang jin, tang min
yang jie » yang jin, yang di, yang jui
hong shu » cong shu, tong shui, wong shiu

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

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