London, 1971 "Levey (1987)": Levey, Michael, The National Gallery Collection, 1987, National Gallery Publications, Stratford, Jenny, pages as specified, in Richard II's Treasure; the riches of a medieval king, website by The Institute of Historical Research and Royal Holloway, University of London, 2007 Pamela Tudor-Craig, in: Jonathan Alexander & Paul Binski (eds), Age of Chivalry, Art in Plantagenet England, 1200–1400, Royal Academy/Weidenfeld & Nicolson, London 1987 Further reading Gordon, D., Making and meaning: The Wilton Diptych, London: National Gallery, 1993 Gordon, D., Monnas, L. and Elam, C. (eds.), The regal image of Richard II and the Wilton Diptych, London: Harvey Miller, 1997 External links The Wilton Diptych on the National Gallery website The Wilton Diptych at Smarthistory Zoomable image BBC 3D model (on Sketchfab) Angels in art Gothic paintings Collections of the National Gallery, London Diptychs International Gothic Paintings of the Madonna and Child Paintings depicting John the Baptist Portraits of the English royal family Sheep in art Works of unknown authorship