Perhaps you should try some spelling variations:
union conversations » win conversations, design conversations, driven conversations
design conclusions » design conclusion
20th century » 18th century
2017 germany » 20 germany, 17 germany, 2006 germany
reef history » brief history, reeves history, reef fishery
etf history » imf history, ref history, tnf history
2f history » imf history, ref history, tnf history
21 germany » 2.1 germany, 11 germany, 2 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: %22christian ((union conversations) OR (design conclusions)) %((21 germany) OR (2017 germany)) %((2f history) OR (((etf history) OR (reef history)))) %2f 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22christian ((union conversations) or (design conclusions)) %((21 germany) or (2017 germany)) %((2f history) or (((etf history) OR (reef history)))) %2f 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %22christian ((union conversations) or (design conclusions)) %((21 germany) or (2017 germany)) %((2f history) or (((etf history) OR (reef history)))) %2f 20th century%22*.