Perhaps you should try some spelling variations:
pdf statistisch » auf statistisch, d statistisch, auf statistische
edf statistics » adf statistic, f statistics, motif statistics
2f statistics » f statistics, motif statistics, proof statistics
2c vital » 23 vital, _ vital, a vital

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: %22iceland %((2f statistics) OR (((edf statistics) OR (pdf statistisch))))%2c vital%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22iceland %((2f statistics) or (((edf statistics) OR (pdf statistisch))))%2c vital%22".
• Adding a wildcard symbol may retrieve word variants: %22iceland %((2f statistics) or (((edf statistics) OR (pdf statistisch))))%2c vital%22*.