1. J. Richardson, with the collaboration of M.M. McCully in A Life of Picasso 1907–1917: the Painter of Modern Life, vol. II, Jonathan Cape, London, 1996, p. 223.
2. Penrose's diary, ‘visit to Picasso: 21 March 1955, Paris’, Penrose Archives, Edinburgh, UK.
3. The Autobiography of Alice B. Toklas;Stein,1933
4. F. Koussiaki, http://www.clevelandart.org/exhibcef/picassoas/html/2325903.html, published October 2001.