Perhaps you should try some spelling variations:
numerische mathematical » numerical mathematical, numerischen mathematik, american mathematical
numerical mathematics » industrial mathematics, general mathematics
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 (((numerische mathematical) OR (numerische mathematik)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "international series of ((numerical mathematics) or (((numerische mathematical) OR (numerische mathematik))))".
• Adding a wildcard symbol may retrieve word variants: international series of ((numerical mathematics) or (((numerische mathematical) OR (numerische mathematik))))*.