William Gordon Perrin: British flags, their early history, and their development at sea; with an account of the origin of the flag as a national device. Kapitel IV: Flags of Command: Pendants of Command, Commodores. Cambridge University Press, Cambridge 1922, S. 102; Textarchiv– Internet Archive.
William Gordon Perrin: British flags, their early history, and their development at sea; with an account of the origin of the flag as a national device. Cambridge University Press, Cambridge 1922, S. 73–109; Textarchiv– Internet Archive.