Peter Fleming, The Siege at Peking: The Boxer Rebellion, illustrated, Dorset Press, 1990, p. 98, ISBN 0-88029-462-0.
«Tung Fu-hsiang's Moslem cavalry, flaunting banners of scarlet and black but armed with modern Mausers, were however treated with great respect. They had taken a leading part in anti-foreign incidents two years earlier, and when on 17 June, after a stone-throwing incident, a detachment of them was fired on by the Germans, Sir Claude MacDonald sent a tactful reproof to Baron Von Ketteler, urging strict precautions against all acts of provocation; 'When our own troops arrive we may with safety assume a different tone, but it is hardly wise now.'»