Perhaps you should try some spelling variations:
mathematika » mathematical, mathematiker, mathematicae
mathematica » mathematical, mathematics, mathematician
mathematikern » mathematiker
mathematiklehrer » mathematiker

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