Perhaps you should try some spelling variations:
undergebnisse der » endergebnisse der, ergebnisse der, hauptergebnisse der
ihre grenzgebiete » ihren grenzgebieten, die grenzgebiete, im grenzgebiet
modern surgery » open surgery, modern slavery
modern survey » model survey, modeling survey, modern supply
models survey » modeling survey, models supply
12c a » 12c _
2c a » 2 a, c a, 20 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: %undergebnisse der (mathematik OR mathematical) und ihre grenzgebiete. 2. folge%((2c a) OR (12c a)) series of ((((((modern survey) OR (models survey))s) OR (modern surgery))) OR (((modern survey) OR (models survey)))) in mathematics%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%undergebnisse der (mathematik or mathematical) und ihre grenzgebiete. 2. folge%((2c a) or (12c a)) series of ((((((modern survey) OR (models survey))s) or (modern surgery))) or (((modern survey) OR (models survey)))) in mathematics%22".
• Adding a wildcard symbol may retrieve word variants: %undergebnisse der (mathematik or mathematical) und ihre grenzgebiete. 2. folge%((2c a) or (12c a)) series of ((((((modern survey) OR (models survey))s) or (modern surgery))) or (((modern survey) OR (models survey)))) in mathematics%22*.