Catalogues Raisonnés

• MacDonald, Margaret F., James McNeill Whistler. Drawings, Pastels and Watercolours. A Catalogue Raisonné, New Haven and London, 1995 (cat. no. 704) as " 'The Owl' very ill in bed".

Websites

• The Correspondence of James McNeill Whistler, 1855-1903, edited by Margaret F. MacDonald, Patricia de Montfort and Nigel Thorp; including The Correspondence of Anna McNeill Whistler, 1855-1880, edited by Georgia Toutziari. Online edition, University of Glasgow, 2003-2005. GUW #02800.