Perhaps you should try some spelling variations:
curious conversations » curious conversion, serious conversation, courageous conversations
reef history » brief history, reeves history, reef fishery
etf history » imf history, ref history, tnf history
20 germany » 2 germany, 7 germany, 8 germany
21 germany » 2.1 germany, 11 germany, 2 germany

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 curious conversations %((20 germany) OR (21 germany)) %((etf history) OR (reef history)) %2f 18th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22christian curious conversations %((20 germany) or (21 germany)) %((etf history) OR (reef history)) %2f 18th century%22".
• Adding a wildcard symbol may retrieve word variants: %22christian curious conversations %((20 germany) or (21 germany)) %((etf history) OR (reef history)) %2f 18th century%22*.