Killeen, R. R., & O'Brien, A. P. (1923). Correspondence and other documents relating to a controversy within the Sinn Féin Roger Casement Cumann (London) following Father James O’Connell's denunciation of Art Ó Briain and Seán McGrath as traitors for expressing the opinion in court that the anti-Treaty Irish Republican Army was incapable of military victory.

Killeen, Rose Rosie, and Art Patrick O'Brien. Correspondence and Other Documents Relating to a Controversy Within the Sinn Féin Roger Casement Cumann (London) Following Father James O’Connell's Denunciation of Art Ó Briain and Seán McGrath as Traitors for Expressing the Opinion in Court That the Anti-Treaty Irish Republican Army Was Incapable of Military Victory. 1923.