Tolong jelaskan mengenai Karya yang dikutip dari Karl Valentin

Benjamin, Walter. 1983. Understanding Brecht. Trans. Anna Bostock. London and New York: Verso. .

Brecht, Bertolt. 1965. The Messingkauf Dialogues. Trans. John Willett. Bertolt Brecht: Plays, Poetry, Prose Ser. London: Methuen, 1985. .

Calandra, Denis. 2003. "Karl Valentin and Bertolt Brecht." In Popular Theatre: A Sourcebook. Ed. Joel Schechter. Worlds of Performance Ser. London and New York: Routledge. p. 189-201. .

Horwitz, Kurt "Karl Valentin in einer anderen Zeit," Stürzflüge im Zuschauerraum (Munich, Piper Verlag, 1970), pp. 16–17

McDowell, W. Stuart. 1977. "A Brecht-Valentin Production: Mysteries of a Barbershop", in Performing Arts Journal, Vol. 1, No. 3 (Winter, 1977), pp. 2–14.

McDowell, W. Stuart. 2000. “Acting Brecht: The Munich Years,"  in The Brecht Sourcebook, Carol Martin, Henry Bial, editors (Routledge, 2000) p. 71 - 83.

Schechter, Joel. 1994. "Brecht's Clowns: Man is Man and After". In Thomson and Sacks (1994, 68-78).

Thomson, Peter and Glendyr Sacks, eds. 1994. The Cambridge Companion to Brecht. Cambridge Companions to Literature Ser. Cambridge: Cambridge University Press. .

Willett, John. 1967. The Theatre of Bertolt Brecht: A Study from Eight Aspects. Third rev. ed. London: Methuen, 1977. .

Willett, John and Ralph Manheim. 1970. Introduction. In Collected Plays: One by Bertolt Brecht. Ed. John Willett and Ralph Manheim. Bertolt Brecht: Plays, Poetry and Prose Ser. London: Methuen. . p.vii-xvii.