'Die Geschichte vom braven Zauberer' in Der Schmetterling (2 June 1932).
Rudi Keller was one of the illustrators who worked for the children's magazine Der Schmetterling, published by Verlag Steinsberg in Vienna from 1926 until 1941.
'Der hohle Zahn'.
Keller's front page comic pages, unusually arranged with four panels plus one unrelated panel in the middle, the latter drawn by Zelger.
Comics from Der Schmetterling (2 March 1931).