O'Sullivan, Charles Edward (2019) Migrant access to welfare payments in Ireland and the impact of Europeanisation: Comparing EU citizens and third-country national labour migrants. PhD thesis, National University of Ireland Maynooth.
Ferri, Delia and O'Sullivan, Charles Edward (2016) The Impact of the Economic Crisis on the Irish Legal System. Between Austerity and Constitutional Rhetoric. Federalismi.it, 26. pp. 1-29. ISSN 1826-3534
Ferri, Delia, Giannoumis, Anthony and O'Sullivan, Charles Edward (2015) Fostering accessible technology and sculpting an inclusive market through regulation. International Review of Law, Computers & Technology, 29 (2-3). pp. 81-87. ISSN 1360-0869