Perhaps you should try some spelling variations:
christian oboen » christian boehm, christian onof, christian order
christian about » christians about, christian labour, christian account
20th century » 18th century
tnf history » imf history, etf history, motif history
ref history » reef history, brief history, bief history
2f germany » 2 germany, 20 germany, 21 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 oboen) OR (christian about)) conversations %2f germany %((tnf history) OR (ref history)) %2f 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((christian oboen) OR (christian about)) conversations %2f germany %((tnf history) or (ref history)) %2f 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %((christian oboen) OR (christian about)) conversations %2f germany %((tnf history) or (ref history)) %2f 20th century%22*.