Perhaps you should try some spelling variations:
"mathematical fur das lehramt" » "mathematical form das lehramt", "mathematical fluid das lehramt", "mathematical fuzzy das lehramt", "mathematical fur des lehramts"
"mathematica fur das lehramt" » "mathematisch fur das lehramt", "mathematica kurz das lehramt", "mathematik fur das lehramt", "mathematica fur des lehramts"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"mathematical fur das lehramt\") OR (\"mathematica fur das lehramt\"))".
• Removing quotes may allow a broader search: (( mathematical fur das lehramt ) OR ( mathematica fur das lehramt )).
• Adding a wildcard symbol may retrieve word variants: (("mathematical fur das lehramt") OR ("mathematica fur das lehramt"))*.