Perhaps you should try some spelling variations:
lang yanling » wang yanling, wang yangming, zhang yunling
yanling yang » yang yang, ying yang
der tests » des tests, der trusts, user tests
der test » der text, per test, der texte
kit song » kim song, art song, jin song
jie song » jae song, jin song, kim song

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

• Performing a fuzzy search may retrieve terms with similar spellings: lang yanling yang ((der test) or (der tests)) ((kit song) or (jie song)) cong shu ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: lang yanling yang ((der test) OR (der tests)) ((kit song) OR (jie song)) cong shu ;.
• Adding a wildcard symbol may retrieve word variants: lang yanling yang ((der test) or (der tests)) ((kit song) or (jie song)) cong shu ;*.