^The Concise Cinegraph: Encyclopaedia of German Cinema, ed. Hans-Michael Bock and Tim Bergfelder, Film Europa 1, New York/Oxford: Berghahn, 2009, ISBN9781571816559, p. 138.
^ abcUrsula Hardt, From Caligari to California: Erich Pommer's Life in the International Film Wars, Providence, Rhode Island: Berghahn, 1996, ISBN9781571819307, p. 227.