T C Barker and Michael Robbins, A History of London Transport, Volume two – the Twentieth Century to 1970, George Allen & Unwin Ltd, 1974 Cooke, B.W.C., ed.
T C Barker and Michael Robbins, A History of London Transport, Volume two – the Twentieth Century to 1970, George Allen & Unwin Ltd, 1974 Cooke, B.W.C., red.