Perhaps you should try some spelling variations:
modern purveyors » modern purgatory, power purveyor
modern surveys » oder surveys, modern surgery, models survey
modern survey » modern surgery, models survey, model survey

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 im grenzgebiet. 2. folge, a series of ((((modern surveys) OR (modern purveyors))) OR (modern survey)) in mathematics.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ergebnisse der mathematik und im grenzgebiet. 2. folge, a series of ((((modern surveys) OR (modern purveyors))) or (modern survey)) in mathematics".
• Adding a wildcard symbol may retrieve word variants: ergebnisse der mathematik und im grenzgebiet. 2. folge, a series of ((((modern surveys) OR (modern purveyors))) or (modern survey)) in mathematics*.