Hallo,
from the commercial sign on the left side, the architecture of the houses and the name of the picture (***bilzen*), i think that this is not a german city , but the town Bilzen in Belgium.
The photo may be ok for your needs, but as the commercial sign is not in german, you may rethink your choice.
Take a look on EBAY.de (search for "Ansichtskarten", and then "Deutschland") . You will find what yo need.
Cheers
Claude