Jean-Philippe Huys and Dominique Marechal, Realism: From Living Art to Free Art, in: Howe, Jeffery W., (editor), Courbet: mapping realism: paintings from the Royal Museums of Fine Arts of Belgium and American collections by Courbet, Gustave, 1819-1877, McMullen Museum of Art; Royal Museums of Fine Arts of Belgium, 2013, p. 24-25