Perhaps you should try some spelling variations:
soziale conditions » sale conditions, mobile conditions, scale conditions
smale conditions » smale condition, sale conditions, stable conditions
20 united » 10 united, 2 united, 2002 united
2f 21st » 2 21st, 20 21st, 21 21st
11 21st » 1 21st, 2011 21st

Try widening your search to All Fields.

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: %22teenagers %20 united states %auf ((soziale conditions) OR (smale conditions)) %((2f 21st) OR (11 21st)) century%22.
• Adding a wildcard symbol may retrieve word variants: %22teenagers %20 united states %auf ((soziale conditions) or (smale conditions)) %((2f 21st) or (11 21st)) century%22*.