YouTube - RTEWhy did Edward Carson not become Northern Ireland’s Prime Minister? video clip, 2021
Google Arts and CultureMemorandum from Arthur Griffith to de Valera on Ulster open_in_new document, 8 November 1921
National Portrait GalleryThe Mad Bull (James Craig, 1st Viscount Craigavon; Michael Collins) cartoon, 15 February 1922
Documents on Irish Foreign Policy Extract from statement by Michael Collins on Northern Ireland policy open_in_new document, 4 February 1922