Perhaps you should try some spelling variations:
numerischen mathematik » numerische mathematik
numerical mathematics » industrial mathematics, general mathematics, numerische mathematik
international series » international services, international serious, international serials

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: international series of ((numerical mathematics) OR (numerischen mathematik)).
• Adding a wildcard symbol may retrieve word variants: international series of ((numerical mathematics) or (numerischen mathematik))*.