Perhaps you should try some spelling variations:
curious conversations » serious conversation, courageous conversations, conscious conversations
curious conversion » curious confession, cur's conversion, riots conversion
20th century » 18th century
ref history » reef history, bief history, imf history
2 germany » 7 germany, 2 german, 8 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 ((curious conversations) OR (curious conversion)) %2 germany %((brief history) OR (ref history)) %2f 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22christian ((curious conversations) OR (curious conversion)) %2 germany %((brief history) or (ref history)) %2f 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %22christian ((curious conversations) OR (curious conversion)) %2 germany %((brief history) or (ref history)) %2f 20th century%22*.