См., напр.: M. de Waha, 'La lettre d'Alexis Comnène à Robert Ier le Frison', Byzantion 47 (1977), pp. 113–25; J. Shepard, 'Aspects of Byzantine attitudes and policy towards the West in the 10th and 11th centuries', Byzantinische Forschungen 13 (1988), pp. 106–12.
