Perhaps you should try some spelling variations:
mathematika » mathematica, mathematical, mathematiker, mathematicala
mathematik » mathematical
mathematikums » mathematicalums, mathematikers, mathematikbuch, mathematiker
mathematiklehrer » mathematicallehrer, mathematiker, mathematikern

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 mathematik) OR (mathematikums OR mathematiklehrer)).
• Adding a wildcard symbol may retrieve word variants: ((mathematika or mathematik) or (mathematikums or mathematiklehrer))*.