Perhaps you should try some spelling variations:
upon conversations » union conversations, spoken conversations, human conversations
open conversations » agent conversations, roman conversations, content conversations
20th century » 18th century
bief history » brief hystory, imf history, reef history
ref history » reef history, imf history, tnf history
etf history » reef history, imf history, tnf history
21 germany » 2.1 germany, 11 germany, 2 germany
2f germany » 2 germany, 20 germany, 25 germany
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: %christian ((upon conversations) OR (open conversations)) %((2f germany) OR (21 germany)) %((((etf history) OR (ref history))) OR (((bief history) OR (brief history)))) %2f 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%christian ((upon conversations) OR (open conversations)) %((2f germany) or (21 germany)) %((((etf history) or (ref history))) or (((bief history) or (brief history)))) %2f 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %christian ((upon conversations) OR (open conversations)) %((2f germany) or (21 germany)) %((((etf history) or (ref history))) or (((bief history) or (brief history)))) %2f 20th century%22*.