Vaughan's series of books on Valois Burgundy have long been a staple for anyone interested Burgundian history and culture. After a long stretch of being out of print, and very difficult to find, these new editions are sure to be welcomed by many historians. Added to Vaughan's work is a fantastic new introduction written for the 2002 edition by Malcolm Vale (another historian I would readily recommend).
While these works may be older, and more recent work has been done on Burgundy, Vaughan's scholarship is still first-rate. A must for the bookshelf of anyone interested in Valois Burgundy, or Northern Europe in the late 14th and 15th centuries.