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
Hathi Trust Digital LibraryThe struggle of the Irish people. Address to the Congress of the United States book, January 1921
UCD History HubAftermath of The Rising and 1917 By-Elections. (The Irish Revolution Lecture 5) podcast, 2014
Flickr - NLIThe shell of the G.P.O. on Sackville Street after the 1916 Rising photograph, May 1916