Perhaps you should try some spelling variations:
thinking losing » thinking long, thinking using, thinking leading
4 abstract » 1 abstract, 3 abstract, 4.1 abstract
2 abstract » 1 abstract, 3 abstract, 3.2 abstract
yan yang » yang yang, yao yang, dan yang
sie sich » die sich, wie sich, die sicht
wang » wing, wan
und » fund

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

• Performing a fuzzy search may retrieve terms with similar spellings: (wang OR lang) yan yang ((4 abstract) or (2 abstract)) thinking losing ((sie sich) or (und die)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (wang OR lang) yan yang ((4 abstract) OR (2 abstract)) thinking losing ((sie sich) OR (und die)) ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(wang OR lang) yan yang ((4 abstract) or (2 abstract)) thinking losing ((sie sich) or (und die)) ;*".