1. Leahy, Thomas . ‘Informers, Agents, the IRA and British Counter-Insurgency Strategy during the Northern Ireland Troubles 1969 to 1998’. King’s College London: Unpublished PhD, 2015.
2. 326 Whyte, John . ‘How Much Discrimination Was There Under the Unionist Regime, 1921–1968?’, Contemporary Irish Studies (1983): http://cain.ulst.ac.uk/issues/discrimination/whyte.htm.
3. Ware, John . ‘Exposed: The Murky World of Spying during the Troubles’, Irish Times, 11 April 2017: www.irishtimes.com/news/ireland/irish-news/exposed-the-murky-world-of-spying-during-the-troubles-1.3043818.
4. ‘UVF Killed Sam Marshall as Eight Soldiers Watched – Cover-Up’. An Phoblacht, 2 April 2012: www.anphoblacht.com/contents/1423.