Sources consulted for this project are referenced below. 

  • Ainsworth, Maryan W. “Caveat emptor: An Early Twentieth-Century Workshop for Flemish Primitives.”Apollo153, 427 (2001): 20–29.

  • Ainsworth, Maryan W, and Keith Christiansen. From Van Eyck to Bruegel: Early Netherlandish Painting in the Metropolitan Museum of Art. New York: Metropolitan Museum of Art, 1998.

  • Amore, Anthony M.The Art of the Con: The Most Notorious Fakes, Frauds, and Forgeries in the Art World. New York: Palgrave Macmillan, 2015.

  • Charney, Noah. Stealing the Mystic Lamb: The True Story of the World’s Most Coveted Masterpiece. New York: Public Affairs, 2010.

  • Duda, Larry. "Biography - Friedrich G. Helfferich." American Chemical Society, Industrial & Englineering Chemistry Research 34, no. 8 (1995): 2551–2552. 

  • Fry, Roger. "The Authenticity of the Renders Collection." The Burlington Magazine for Connoisseurs 50, no. 290 (1927): 261-67.

  • Gordenker, Emilie E. S. “The Rhetoric of Dress in Seventeenth-Century Dutch and Flemish Portraiture.” The Journal of the Walters Art Gallery57, Place and Culture in Northern Art (1999): 87–104.

  • Hand, John Oliver. Joos van Cleve: The Complete Paintings.Yale University Press, 2004.

  • Harbison, Craig. The Mirror of the Artist: Northern Renaissance Art in its Historical Context. New York: H.N. Abrams, 1995.

  • Hoving, Thomas. False Impressions: The Hunt for Big-Time Art Fakes. New York: Simon & Schuster, 1996.

  • Lane, Barbara G. Hans Memling: Master Painter in Fifteenth-Century Bruges.London: Harvey Miller, 2009.

  • Leeflang, Micha. Joos van Cleve: A Sixteenth-Century Antwerp Artist and His Workshop. Brepols, 2015.

  • Lenain, Thierry. Art Forgery: The History of a Modern Obsession. London: Reaktion Books, 2012.

  • von Sonnenburg, Hubert. “A Case of Recurring Deception.” The Metropolitan Museum of Art Bulletin, New Series 51, no. 3 (Winter, 1993–1994): 8–19.

  • Snyder, James. Northern Renaissance Art: Painting, Sculpture, and Graphic Arts from 1350 to 1575. Second edition. Upper Saddle River, New Jersey: Prentice Hall, 2005.

  • Stroo, Cyriel, et al. The Flemish Primitives: Catalogue of Early Netherlandish Painting in the Royal Museums of Fine Arts of Belgium. 6 vols. Brussels: Brepols, 1996. 

  • Vanwijnsberghe, Dominique, Catherine Fondaire, and Catherine Bourguignon. Autour de la Madeleine Renders: un aspect de l'histoire des collections, de la restauration et de la contrefaçon en Belgique dans la première moitié du XXe siècle. Bruxelles: Institut Royal du Patrimoine Artistique, 2008.

  • Vos, Dirk de. Hans Memling: The Complete Works. Ludion Press, 1994.