(EN) Sir Peter Matthews, su telegraph.co.uk, The Telegraph. URL consultato il 5 ottobre 2020.
ukwhoswho.com
(EN) 'HAYES, Sir Brian', Who's Who 2017, A & C Black, an imprint of Bloomsbury Publishing plc, 2017; online edn, Oxford University Press, 2016; online edn, Nov 2016 accessed 4 Nov 2017
(EN) 'WILLIAMS, David John', Who's Who 2017, A & C Black, an imprint of Bloomsbury Publishing plc, 2017; online edn, Oxford University Press, 2016; online edn, Nov 2016 accessed 4 Nov 2017