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
wang wang » wang liang, wang yan, wang yong
wang yang » wang yan, wang liang, wang yanling
sie sich » die sich, wie sich, die sicht
sind ein » und ein, sind die, sind wir

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

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