Spieth, D. A. (2011). All that happened had to happen: Walter Bortolossi / Text by Darius A. Spieth ; published by Louisiana State University School of Art. Louisiana State University Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSpieth, Darius A. All That Happened Had to Happen: Walter Bortolossi / Text by Darius A. Spieth ; Published by Louisiana State University School of Art. Baton Rouge: Louisiana State University Press, 2011.
एमएलए (8वां संस्करण) प्रशस्ति पत्रSpieth, Darius A. All That Happened Had to Happen: Walter Bortolossi / Text by Darius A. Spieth ; Published by Louisiana State University School of Art. Louisiana State University Press, 2011.
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