The textbook Menschen is used in our A1, A2 and B1 German courses.
Sicher! or Aspekte Neu are the textbooks for our B2 and C1 German courses.
You can buy the books in the Okerstr. 1 (U-Leinsetraße) at the bookshop Buchhafen or at Hugendubel and there are two nearby branches: One at Karstadt on Hermannplatz and another in the Neukölln Arcaden shopping center right by U-Rathaus-Neukölln.
Please make sure that you get these exact books when buying Menschen textbooks:
(there’s another exercise book saying “HIER” on the cover, but that’s the wrong one).