Perhaps you should try some spelling variations:
curious conversations » curious conversion, serious conversation, conscious conversations
reef history » brief history, reeves history, reef fishery
20th century » 18th century
2.1 germany » 21 germany, 2017 germany, 9.13 germany
imf history » brief history
2f 20th » 20 20th, 2.2 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: %22christian ((curious conversations) OR (courageous conversations)) %2.1 germany %((reef history) OR (imf history)) %2f 20th century%22.
• Adding a wildcard symbol may retrieve word variants: %22christian ((curious conversations) or (courageous conversations)) %2.1 germany %((reef history) or (imf history)) %2f 20th century%22*.