'HAMILTON, Sir Robert William', Who Was Who, A & C Black, an imprint of Bloomsbury Publishing plc, 1920–2015; online edn, Oxford University Press, 2014; online edn, April 2014 retrieved 17 June 2015
'HAMILTON, Sir Robert William', Who Was Who, A & C Black, an imprint of Bloomsbury Publishing plc, 1920–2015; online edn, Oxford University Press, 2014; online edn, April 2014 retrieved 17 June 2015