Félix Achard. Revue du Salon des Beaux-Arts de Limoges. Limoges, 1870, p. 12, calls it "Le Sommeil" and comments that it seems to be a project for one of the "grands panneaux" due to its "certaine négligence de dessin".
Philippe Burty. "L'Exposition de Limoges." Gazette des beaux-arts, 2nd ser., 4 (September 1870), p. 222, in a review of the 1870 Limoges exhibition, states that Puvis lent three studies or reduced versions of his grand decorative compositions, including one for "Sleep".
Pierre Puvis de Chavannes. Letter. April 1, 1870 [excerpt published in French and English in Ref. Price 2010, p. 129], writes that he may send an almost–finished version of "Sleep" [probably this picture] to an exhibition in Limoges.
André Michel and J[ean]. Laran. Puvis de Chavannes. Philadelphia, 1912, pl. XV, reproduce our picture with a discussion of the version shown in the Salon of 1867 (Musée des Beaux-Arts, Lille; Price no. 151).
A. Declairieux. Puvis de Chavannes et ses oeuvres trois conférences. Lyons, 1928, pp. 89–90, ill., erroneously states that it was exhibited in the Salon of 1864 and locates it in the Musée des beaux-arts, Lille.
Camille Mauclair. Puvis de Chavannes. Paris, 1928, p. 162.
Bryson Burroughs. "The Theodore M. Davis Bequest: The Paintings." Metropolitan Museum of Art Bulletin 26, section 2 (March 1931), pp. 15–16, ill. p. 18, calls it a study for or a small replica of the Lille painting (Price no. 151).
R. Graul in Allgemeines Lexikon der bildenden Künstler. 27, Leipzig, 1933, p. 474, lists it as a study for the Lille picture.
Charles Sterling and Margaretta M. Salinger. "XIX Century." French Paintings: A Catalogue of the Collection of The Metropolitan Museum of Art. 2, New York, 1966, pp. 227–28, ill., note that the completeness of this picture suggests that it is a reduced repetition of the Lille painting.
Aimée Brown Price. "A Puvis de Chavannes Gouache in the MSU Art Collection." Kresge Art Center Bulletin 2 (October 1968), unpaginated, ill., mentions it in relation to a gouache version of the composition in the collection of Michigan State University.
Richard J. Wattenmaker. Puvis de Chavannes and the Modern Tradition. Exh. cat., Art Gallery of Ontario. Toronto, 1975, p. 28, mentions that Davis lent this picture to the MMA in 1915 for a small exhibition of eight Puvis paintings.
Jacques Foucart in Puvis de Chavannes, 1824–1898. Exh. cat., Grand Palais, Paris. Ottawa, 1977, p. 86, under no. 63, p. 249, letter no. 231 [French ed., Paris, 1976, p. 88, under no. 63, p. 251, letter no. 231], calls it a reduced version of the Lille painting, noting that it could be the version referred to by Puvis in a letter of October 7, 1867 or alternately, the one mentioned as almost finished on April 1, 1870 [Ref. Puvis de Chavannes 1870]; states that the artist associated the Lille painting with a verse from Virgil's "Aeneid".
Udo Kultermann. "Woman Asleep and the Artist." Artibus et Historiae no. 22 (1990), p. 160 n. 49.
William M. Griswold in Masterworks from the Musée des Beaux-Arts, Lille. Exh. cat., The Metropolitan Museum of Art. New York, 1992, p. 277, under no. 85.
Aimée Brown Price. Pierre Puvis de Chavannes. Exh. cat., Van Gogh Museum. Amsterdam, 1994, pp. 13, 116–18, no. 47, ill. (color), calls it "Sleep/Le Sommeil (reduced version)" and dates it about 1867–70; discusses the influence of Chassériau's "Harvesters at Rest" and "Christ in the Garden of Olives" (both Musée du Louvre, Paris); notes that this was the version most likely shown in Limoges in 1870.
Kathryn Calley Galitz in The Masterpieces of French Painting from The Metropolitan Museum of Art: 1800–1920. Exh. cat., Museum of Fine Arts, Houston. New York, 2007, pp. 66, 249, no. 43, ill. (color and black and white).
Aimée Brown Price. "The Artist and His Art." Pierre Puvis de Chavannes. 1, New Haven, 2010, p. 165.
Aimée Brown Price. "A Catalogue Raisonné of the Painted Work." Pierre Puvis de Chavannes. 2, New Haven, 2010, pp. 125, 128–29, no. 152, ill., states that it postdates the Lille painting and may have been executed in 1870, based on Puvis's April 1, 1870 letter [see Ref.].