Handbook of British chronology / ed. F. M. Powicke ; with the assistance by W.J. Harte, Charles Johnson and W.J. Harte. - Powicke, F. M., 1879-1963; Johnson, Charles, M.A., F.B.A., C.B.E; Harte, W. J., M.A (Royal Historical Society Guides and Handbooks ;, 1939)