Perhaps you should try some spelling variations:
mathematika » mathematica, mathematical, mathematiker
mathematicala » mathematical, mathematicals, mathematicaland
mathematikums » mathematikbuch, mathematiker
mathematikern » mathematiker
mathematikers » mathematiker, mathematiklehrer, mathematiklernen

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: (((mathematika OR mathematicala) OR mathematik) OR ((mathematikums OR mathematikern) OR mathematikers)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((mathematika or mathematicala) or mathematik) or ((mathematikums OR mathematikern) or mathematikers))".
• Adding a wildcard symbol may retrieve word variants: (((mathematika or mathematicala) or mathematik) or ((mathematikums OR mathematikern) or mathematikers))*.