Coba jelasin Kesusastraan dari Walter Mehring dong

Allen, Roy F.: Literary Life in German Expressionism and the Berlin Circles. UMI Research Press, 1983.

Thomson, Philip John: The Grotesque in German Poetry, 1880-1933. Hawthorn Press, 1975.

Spalek, John M./Bell, Robert F.: Exile, the Writer's Experience, University of North Carolina Press, 1982.