Recueil des historiens des Gaules et de la France,vol. 23 (1894) p. 450 "Ex obituario ecclesiae Augensis"
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[[#CITEREF|]] remarks on an inconsistency by P. van Kerrebrouck, who in his Les Valois (1990) p. 261 states that John died after his father, i.e. in 1416 or after, but in his La Maison de Bourbon: 1256-1987 (1987) p. 91 gives John's date of death as 1399.
