Hopkinson, Michael (2010). "I: From Treaty to Civil War, 1921-2". In Hill, J. R. (ed.). A New History of Ireland Volume VII: Ireland, 1921-84. Oxford University Press. p. 13. ISBN9780191615597. Archived from the original on 11 June 2020. Retrieved 9 June 2020.
Hopkinson, Michael (2010). "I: From Treaty to Civil War, 1921-2". In Hill, J. R. (ed.). A New History of Ireland Volume VII: Ireland, 1921-84. Oxford University Press. p. 13. ISBN9780191615597. Archived from the original on 11 June 2020. Retrieved 9 June 2020.