Perhaps you should try some spelling variations:
change learning » exchange earnings, enhanced learning, machine learning
gender change » gender age
yang guang » yang yang, yan guan
yang liang » wang liang, yan liang, yang yang
z gender » 2 gender, 3 gender, 1 gender
note sub » note sur, date sub
spur » sur

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 ((yang guang) OR (yang liang)) z gender change learning ((note sub) OR (der spur)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang ((yang guang) OR (yang liang)) z gender change learning ((note sub) or (der spur)) ;~".
• Adding a wildcard symbol may retrieve word variants: wang ((yang guang) OR (yang liang)) z gender change learning ((note sub) or (der spur)) ;*.