Perhaps you should try some spelling variations:
ying yang » yang yang, ying chang, wang yang
song rong » song chong, hong song, song bing
yin yang » yi yang, yin fang, yin hang
per test » der tests, per cent, asr test
der test » der tests, der text, der texte
kit song » kim song, art song, jie song
rong su » rong yu, cong sun, jeong su

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

• Performing a fuzzy search may retrieve terms with similar spellings: lang ((ying yang) OR (yin yang)) ((per test) or (der test)) kit song rong su ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: lang ((ying yang) OR (yin yang)) ((per test) OR (der test)) kit song rong su ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "lang ((ying yang) OR (yin yang)) ((per test) or (der test)) kit song rong su ;".
• Adding a wildcard symbol may retrieve word variants: lang ((ying yang) OR (yin yang)) ((per test) or (der test)) kit song rong su ;*.