Perhaps you should try some spelling variations:
20th century » 18th century
21 germany » 8 germany, 6 germany, 4 germany
11 germany » 11 german, 1918 germany, 8 germany
20 germany » 8 germany, 6 germany, 4 germany
2 germany » 2 german, 8 germany, 6 germany
5 germany » 5 german, 8 germany, 6 germany
2f 20th » 20 20th, 2.2 20th

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: %22agriculture AND state %((2 germany) OR (((((21 germany) OR (((11 germany) OR (7 germany))))) OR (((20 germany) OR (5 germany)))))) %brief history %2f 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((2 germany) or (((((21 germany) or (((11 germany) OR (7 germany))))) or (((20 germany) or (5 germany)))))) %brief history %2f 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((2 germany) or (((((21 germany) or (((11 germany) OR (7 germany))))) or (((20 germany) or (5 germany)))))) %brief history %2f 20th century%22*.