Christopher Riopelle is Curator of Post-1800 Painting at the National Gallery, London; he co-authored Renoir Landscapes: 1865-1883 (2007). Elizabeth Cowling is Professor Emeritus of History of Art at Edinburgh University. Her publications include Visiting Picasso: The Notebooks and Letters of Roland Penrose (2006). Susan Grace Galassi is Curator at the Frick Collection, New York. Anne Robbins is Assistant Curator of Post-1800 Painting at the National Gallery London. She wrote Cezanne in Britain (2006).