Perhaps you should try some spelling variations:
london mathematical » non mathematical, common mathematical, motion mathematical
theory student » theory students, theory studien, theory studying
theory studie » theory studies, theory study, theory state

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: london mathematical ((theory student) OR (theory studie)) texts.
• Adding a wildcard symbol may retrieve word variants: london mathematical ((theory student) or (theory studie)) texts*.