Maddicott, John (1970): , Oxford, ISBN 0-19-821837-0. McKisack, May (1959): , Oxford, ISBN 0-19-821712-9. Phillips, J.R.S. (1972): , Oxford, ISBN 0-19-822359-5 Phillips, J.R.S. (2004): «Valence, Aymer de, eleventh earl of Pembroke (d. 1324)», , Oxford. Prestwich, Michael (2007): , Oxford, ISBN 978-0-19-922687-0. Tout, Thomas (1918): , Manchester.