Perhaps you should try some spelling variations:
thinking firm » thinking form, thinking from, thinking circa
can thinking » lean thinking, case thinking, a thinking
yang liang » wang liang, yang yang, peng liang
yan liang » wang liang, you liang, yan wang
kann ein » kann eine, kann die, kann man
song jin » song min, shang jin, song shin

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: wai ((yan liang) OR (yang liang)) li can thinking firm ((kann ein) OR (song jin)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wai ((yan liang) OR (yang liang)) li can thinking firm ((kann ein) or (song jin)) ;~".
• Adding a wildcard symbol may retrieve word variants: wai ((yan liang) OR (yang liang)) li can thinking firm ((kann ein) or (song jin)) ;*.