RTE Century Ireland
Sinn Féin leaders arrested over alleged ‘German plot’
open_in_newarticle, 2018
National Archives UK
Irish Settlement: Proposals of the British government
open_in_newdocument, 20 July 1921
Houses of Oireachtas
Correspondence between de Valera and Lloyd George
open_in_newdebate, 14 September 1921
Google Arts and Culture
Memorandum from Arthur Griffith to de Valera on Ulster
open_in_newdocument, 8 November 1921