Perhaps you should try some spelling variations:
when conversations » open conversations, agent conversations, chain conversations
win conversations » ai conversations, ip conversations, iv conversations
20th century » 18th century
imf history » brief history
2f germany » 2 germany, 20 germany, 21 germany
2f history » etf history, ref history, tnf history
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: %christian ((win conversations) OR (when conversations)) %((2f germany) OR (7 germany)) %((2f history) OR (imf history)) %2f 20th century%22*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%christian ((win conversations) OR (when conversations)) %((2f germany) or (7 germany)) %((2f history) or (imf history)) %2f 20th century%22*".