Perhaps you should try some spelling variations:
upon conversations » union conversations, spoken conversations, human conversations
open conversations » agent conversations, roman conversations, content conversations
etf history » reef history, imf history, tnf history
ref history » reef history, brief history, bief history
11 germany » 11 german, 1918 germany, 8 germany

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)) %((7 germany) OR (11 germany)) %((etf history) OR (ref history)) %2f 18th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%christian ((upon conversations) or (open conversations)) %((7 germany) or (11 germany)) %((etf history) OR (ref history)) %2f 18th century%22".
• Adding a wildcard symbol may retrieve word variants: %christian ((upon conversations) or (open conversations)) %((7 germany) or (11 germany)) %((etf history) OR (ref history)) %2f 18th century%22*.