National Archives UK
Irish Settlement: Proposals of the British government
open_in_newdocument, 20 July 1921

Bicycles, Barracks & Bandoliers
Memo regarding Catholic recruitment in the RUC and USC
memo, March 1922
Houses of Oireachtas
Correspondence between de Valera and Lloyd George
open_in_newdebate, 14 September 1921
Decade of Centenaries timeline
Ballytrain RIC barracks captured and sacked by the IRA.
photograph, 1920
RTE Century Ireland
Rebel leader Thomas Ashe arrested for inflammatory speech
open_in_newarticle, 2017
UCD History Hub
Arthur Griffith, Sinn Fein and the IRB (The Irish Revolution Lecture 3)
podcast, 2014