[Gustav Friedrich] Waagen. Treasures of Art in Great Britain. London, 1854, vol. 2, p. 200, as a male portrait by Rembrandt in the Holford collection.
Émile Michel. Rembrandt: His Life, His Work, and His Time. English ed. New York, 1894, vol. 2, p. 236, calls it a portrait of Titus van Rijn and dates it about 1660.
C[ornelis]. Hofstede de Groot. De Rembrandt Tentoonstelling te Amsterdam. Amsterdam, , unpaginated, no. 107.
Malcolm Bell. Rembrandt van Rijn and His Work. London, 1899, pp. 84, 147, as "a portrait of a grave young man supposed to be "Titus,'" about 1660.
Wilhelm [von] Bode with the assistance of C. Hofstede de Groot. The Complete Work of Rembrandt. 6, Paris, 1901, pp. 18, 122, no. 445, pl. 445, as "Titus in a Black Cap with a Budding Moustache," in the Holford collection, London; dates it about 1658.
E. W. Moes. Iconographia Batava: Beredeneerde Lijst van Geschilderde en Gebeeldhouwde Portretten van Noord-Nederlanders in Vorige Eeuwen. 2, Amsterdam, 1905, p. 318, no. 6694-4, as a portrait of Titus, about 1660.
Adolf Rosenberg. Rembrandt, des Meisters Gemälde. 2nd ed. Stuttgart, 1906, pp. 404, 417, ill. p. 337, as a portrait of Titus; dates it about 1658–60.
Adolf Rosenberg. Rembrandt, des Meisters Gemälde. 3rd ed. Stuttgart, 1909, p. 562, ill. p. 418, as Titus, painted about 1658.
C[ornelis]. Hofstede de Groot. A Catalogue Raisonné of the Works of the Most Eminent Dutch Painters of the Seventeenth Century. 6, London, 1916, p. 333, no. 703, as Titus, painted about 1658; mentions a copy attributed to Bol in a private collection in New York.
D. S. Meldrum. Rembrandt's Paintings. London, 1923, p. 199, pl. CCCXLVIII, as Titus, painted about 1659.
The Holford Collection. Oxford, 1924, p. 81, no. 93, pl. LXXXII (frontispiece), as "Portrait of a Young Man," by Rembrandt, painted about 1652–54; states that it cannot be Titus, but is probably an earlier portrait of the man depicted in the 1658 portrait in the Louvre; dates it 1652–54 in text and about 1652 in caption.
Seymour de Ricci. "La collection Holford." Gazette des beaux-arts, 5th ser., 11 (January 1925), pp. 40–41, suggests that this picture and two portraits in the Louvre all represent Titus.
The Holford Collection, Dorchester House. Oxford, 1927, vol. 2, p. 22, no. 129, pl. CXVI.
William Gibson. "The Holford Collection." Apollo 7 (May 1928), p. 202, ill. opp. p. 200 (color), discusses the scholarly controversy regarding the sitter's identity and the date.
Wilhelm R. Valentiner. Rembrandt Paintings in America. New York, 1931, unpaginated, no. 134, pl. 134, as Titus, probably painted in 1658.
A[braham]. Bredius. Rembrandt Gemälde. Vienna, 1935, p. 13, no. 293, pl. 293, doubts that it represents Titus.
Kurt Bauch. Rembrandt Gemälde. Berlin, 1966, p. 22, pl. 417, dates it 1656, and dismisses the identification of the sitter as Titus.
Horst Gerson. Rembrandt Paintings. Amsterdam, 1968, pp. 398, 501, no. 328, ill. p. 399, as "A Young Man with a Beret"; notes that the picturesque interpretation is similar to the portraits of Titus of the late 1650s, though he is not the sitter here.
A[braham]. Bredius. Rembrandt: The Complete Edition of the Paintings. 3rd ed. London, 1969, p. 572, no. 293, ill. p. 223.
Paolo Lecaldano in L'opera pittorica completa di Rembrandt. Milan, 1969, p. 118, no. 347, ill.
Christopher Brown. "Rembrandt's 'Portrait of a Boy'." Connoisseur 193 (November 1976), p. 219 n. 4.
J. Bolten and H. Bolten-Rempt. The Hidden Rembrandt. Milan, 1977, p. 197, no. 450, ill.
Christian Tümpel. Rembrandt: Mythos und Methode. Königstein, 1986, p. 430, no. A102, ill. p. 431, as by a pupil of Rembrandt.
Pierre Cabanne. Rembrandt. [Paris], 1991, p. 151, no. 15, ill., dates it 1656.
Walter Liedtke in "Paintings, Drawings, and Prints: Art-Historical Perspectives." Rembrandt/Not Rembrandt in The Metropolitan Museum of Art: Aspects of Connoisseurship. Exh. cat., The Metropolitan Museum of Art. 2, New York, , pp. 119, 134–36, no. 40, ill. (color), as by an imitator of Rembrandt from the last quarter of the seventeenth century.
Hubert von Sonnenburg. "Paintings: Problems and Issues." Rembrandt/Not Rembrandt in The Metropolitan Museum of Art: Aspects of Connoisseurship. Exh. cat., The Metropolitan Museum of Art. 1, New York, 1995, pp. 30, 128–31, no. 40, ill. (color) and figs. 161 (before restoration), 162 (autoradiograph detail), 163 (autoradiograph), 164 (cleaned state), 165 (color detail), as by a seventeenth-century follower of Rembrandt.
Lene Bøgh Rønberg in Rembrandt? The Master and His Workshop. Exh. cat., Statens Museum for Kunst. [Copenhagen], 2006, p. 293 n. 6, under no. 38.
Walter Liedtke. Dutch Paintings in The Metropolitan Museum of Art. New York, 2007, vol. 2, pp. 708, 774–78, 782, no. 176, colorpl. 176, fig. 222 (eighth autoradiograph).
Old Master & British Paintings, Evening Sale. Christie's, London. December 3, 2013, p. 63, under no. 16.