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 yong » wang yang, wang hyoung, wang yan
yong yang » yang yang, dong yang, ying yang
sie sich » die sich, wie sich, die sicht
sind die » und die

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: wang yong yang ((4 abstract) OR (2 abstract)) thinking losing ((sie sich) OR (sind die)) ;~.
• Adding a wildcard symbol may retrieve word variants: wang yong yang ((4 abstract) or (2 abstract)) thinking losing ((sie sich) or (sind die)) ;*.