Perhaps you should try some spelling variations:
2017 germany » 2006 germany, 21 germany, 1917 germany
20 germany » 2 germany, 7 germany, 8 germany
17 germany » 7 germany, 11 germany, 12 germany
2f 20th » 2.2 20th
20 20th » 90 20th, 2019 20th, 2020 20th

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: %22agriculture AND state %((20 germany) OR (((2017 germany) OR (17 germany)))) %brief history %((2f 20th) OR (20 20th)) century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((20 germany) or (((2017 germany) OR (17 germany)))) %brief history %((2f 20th) or (20 20th)) century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((20 germany) or (((2017 germany) OR (17 germany)))) %brief history %((2f 20th) or (20 20th)) century%22*.