History Ireland Tit-for-tat: the War of Independence in the northern counties open_in_new article, 2012
National Archives UK Letter from General Smuts to Eamon de Valera open_in_new letter, 4 August 1921
Bicycles, Barracks & BandoliersMemo regarding Catholic recruitment in the RUC and USC memo, March 1922
National Museums IrelandThomas Ashe – Easter Greetings, 1918 / Easter card postcard, Easter 1918