(en) Bryan F. Peterson, Learning to see creatively : Design, Color & Composition in Photography, Amphoto Press, , 160 p. (ISBN0-8174-4181-6, lire en ligne)
(en) Steve Caplin, Art and Design in Photoshop, Focal Press, (lire en ligne), p. 35
(en) Sir Joshua Reynolds, Annotations on The art of painting of Charles Alphonse Du Fresnoy, Printed by A. Ward, and sold by J. Dodsley, (lire en ligne), p. 103
(en) George Field, Chromatics; or, The analogy, harmony, and philosophy of colours, David Bogue, Fleet Street, (lire en ligne)
(en) John Thomas Smith, Remarks on rural scenery; with twenty etchings of cottages, from nature; and some observations and precepts relative to the pictoresque., printed for, and sold by Nathaniel Smith ancient Print seller at Rembrandts-Head May's Buildings, St. Martin's Lane, and I. T. Smith, at No 40 Trith Street Soho, (lire en ligne), p. 15–17