District and Branch Cancellations of London 1857 to 1900, J. Parmenter; British Post Office Numbers 1844 - 1906, G. Blundell; The Local Posts of London 1690 - 1840, G. Bludell; Postal Cancellations of London 1840 - 1890, H.C. Westley; Postal History of Great Britain and Ireland , Willcocks (2); The British Postage Stamp of The Nineteenth Century, Robson Lowe; British Postmarks a short History and guide, R.C. Alcock and F.C. Holland etc