Nielsen, H. (1977) “J. R. S. Phillips: Aymer de Valence, Earl of Pembroke 1307-1324. Baronial Politics in the Time of Edward II. At the Clarendon Press, Oxford, 1972. 379 s. £ 6 1/2”., Historisk Tidsskrift, 13. Tilgængelig hos: https://tidsskrift.dk/historisktidsskrift/article/view/51936 (Set: 23 december 2025).