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