Perhaps you should try some spelling variations:
union conversations » win conversations, design conversations, driven conversations
when conversations » open conversations, win conversations, agent conversations
reef history » reeves history, reef fishery
20th century » 18th century
2f germany » 20 germany, 21 germany, 25 germany
2 germany » 2 german, 8 germany, 5 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: %christian ((union conversations) OR (when conversations)) %((2f germany) OR (((2 germany) OR (7 germany)))) %((reef history) OR (((imf history) OR (brief history)))) %2f 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%christian ((union conversations) or (when conversations)) %((2f germany) or (((2 germany) OR (7 germany)))) %((reef history) or (((imf history) or (brief history)))) %2f 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %christian ((union conversations) or (when conversations)) %((2f germany) or (((2 germany) OR (7 germany)))) %((reef history) or (((imf history) or (brief history)))) %2f 20th century%22*.