Douglas, C. (1986). Beyond Reason: Malevich, Matiushin, Arnd Their Circles / von Charlotte Douglas. The spiritual in art : abstract painting 1890 - 1985.
Čikaški stil citiranja (17. izdanje)Douglas, Charlotte. "Beyond Reason: Malevich, Matiushin, Arnd Their Circles / Von Charlotte Douglas." The Spiritual in Art : Abstract Painting 1890 - 1985 1986.
MLA način citiranja (8. izdanje)Douglas, Charlotte. "Beyond Reason: Malevich, Matiushin, Arnd Their Circles / Von Charlotte Douglas." The Spiritual in Art : Abstract Painting 1890 - 1985, 1986.
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