Philip Conisbee. "London and Paris: French Artists at Home and Abroad." Burlington Magazine 128 (July 1986), p. 533, fig. 81.
Marianne Roland Michel. Artistes en voyage au XVIIIe siècle. Exh. cat., Galerie Cailleux, Paris. 1986, unpaginated, no. 7, ill., compares its direct observation of nature to the landscapes of the Barbizon painters.
Jacob Bean in Recent Acquisitions: A Selection, 1986–1987. New York, 1987, pp. 44–45, ill. (color), as "Rocks and Foliage"; notes that Bertin's oil paintings are rare "and as far as we know, this signed oil sketch on paper is unique".
Peter Galassi. Corot in Italy: Open-Air Painting and the Classical-Landscape Tradition. New Haven, 1991, p. 107, colorpl. 122, dates it 1821–29; discusses the transformation of the ravine at Sorrento "from a natural wonder into an artistic motif," reproducing similar paintings by Heinrich Reinhold (1823; Kunsthalle Hamburg) and an unidentified artist, perhaps Michallon (early 1820s; private collection, Paris).
Jeremy Strick in In the Light of Italy: Corot and Early Open-air Painting. Exh. cat., National Gallery of Art. Washington, 1996, p. 211, no. 80, ill. (color), dates it to the early 1820s.
Sarah Faunce in In the Light of Italy: Corot and Early Open-air Painting. Exh. cat., National Gallery of Art. Washington, 1996, p. 201.
Xavier Bray in A Brush with Nature: The Gere Collection of Landscape Oil Sketches. Exh. cat., National Gallery. London, 1999, p. 30, fig. 16 (color), dates it to the early 1820s.
Élisabeth Décultot. "Rome 1820. Les nazaréens et le paysage." Studiolo 2 (2003), pp. 50, 58 n. 44, fig. 13.