Edward Hopper, Hayward Gallery, Whitney Museum of American Art (1981). “Edward Hopper, 1882-1967: Hayward Gallery, London, 11 February to 29 March 1981 : a selection from the exhibition Edward Hopper, the art and the artist held at the Whitney Museum of American Art in New York from 16 September 1980 to 25 January 1981”
Gary Hamel (2012). “What Matters Now: How to Win in a World of Relentless Change, Ferocious Competition, and Unstoppable Innovation”, p.53, John Wiley & Sons