Perhaps you should try some spelling variations:
pela literatura » pena literatura, la literatura, a literatura
del literatura » de literatura, da literatura, e literatura
space studien » space studies, spaces studied, space student
future space » feature space, future scope, future smart

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: future space studien _ filosofia ((del literatura) OR (pela literatura)).
• Adding a wildcard symbol may retrieve word variants: future space studien _ filosofia ((del literatura) or (pela literatura))*.