Wolfgang Van Emden, « Kingship in the Old French epic of revolt » in Kings and Kingship in Medieval Europe (King's College London Medieval Studies 10), London, King's College, 1993 p. 305 - 350
With particular reference to the chansons de geste Girart de Roussillon, Raoul de Cambrai, Renaud de Montauban , Ogier de Danemarche , and Girart de Vienne