Emile Male, The Gothic Image , Religious Art in France of the Thirteen Century, p 165-8, English trans of 3rd edn, 1913, Collins, London (and many other editions) is a classic work on French Gothic church art
Lane, Barbara G,The Altar and the Altarpiece, Sacramental Themes in Early Netherlandish Painting, Harper & Row, 1984, ISBN 0-06-430133-8 analyses all these works in detail. See also the references in the articles on the works.
