Der Baldamus und seine Streiche / Oskar Wöhrle. Berlin: Der Bücherkreis, 1931
“Beginning in 1930 he welcomed the opportunity to become the main designer of books for the socialist book club and publisher Der Bücherkreis, at that time directed by Karl Schröder, a well-known member of the KAPD (German Communist Party). Founded in 1924 by the SPD (Socialist Democratic Party), Der Bücherkreis often gave him far more freedom to design the total book: layout and typography, binding, and book jacket. Here he was able to apply the principles of the New Typography without the usual restraints of other publishers. According to Tschichold, a book had to be designed as an entity, assembled from 'typeface, picture, cover, binding, paper, etc.' From 1930 he would design close to 25 books for Der Bücherkreis until he left for Switzerland in 1933.”
Cees W. de Jong (ed.). Jan Tschichold, master typographer: his life, work & legacy. London: Thames & Hudson, 2008 (p. 48)