^Fryde, E. B.; Greenway, D. E.; Porter, S.; Roy, I. (1986). Handbook of British Chronology (Third Edition, reprinted 2003 ed.). Cambridge: Cambridge University Press. p.402
ISBN0-521-56350-X
^Fryde, E. B.; Greenway, D. E.; Porter, S.; Roy, I. (1986). Handbook of British Chronology (Third Edition, reprinted 2003 ed.). Cambridge: Cambridge University Press. p.402
ISBN0-521-56350-X