Perhaps you should try some spelling variations:
ihrer grenzgebiete » ihre grenzgebiete, ihren grenzgebieten, der grenzgebiete
die grenzgebiete » ihre grenzgebiete, im grenzgebiet, und grenzgebiete
modern surgery » open surgery, modern slavery
modern survey » model survey, modeling survey, modern supply
models survey » modeling survey, models supply
2c a » 12c a, 2 a, c a

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: %ergebnisse der mathematik und ((ihrer grenzgebiete) OR (die grenzgebiete)). 2. folge%2c a series of ((modern surgery) OR (((modern survey) OR (models survey)))) in mathematics%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%ergebnisse der mathematik und ((ihrer grenzgebiete) or (die grenzgebiete)). 2. folge%2c a series of ((modern surgery) or (((modern survey) OR (models survey)))) in mathematics%22".
• Adding a wildcard symbol may retrieve word variants: %ergebnisse der mathematik und ((ihrer grenzgebiete) or (die grenzgebiete)). 2. folge%2c a series of ((modern surgery) or (((modern survey) OR (models survey)))) in mathematics%22*.