| A history of modern Ireland, with a sketch of earlier times | Costigan, Giovanni | Monograph or Collective Volume | Pegasus | 1969 |
| Romantic nationalism : Ireland and Europe | Costigan, Giovanni | Article in Journal | | 1973 |
| The Anglo-Irish conflict, 1919-1922 : a war of independence or systematized murder? | Costigan, Giovanni | Article in Journal | | 1968 |
| The tragedy of Charles O'Conor : an episode in Anglo-Irish relations | Costigan, Giovanni | Article in Journal | | 1943 |
| The treason of Sir Roger Casement | Costigan, Giovanni | Article in Journal | | 1955 |