| Bishop Edward Thomas O'Dwyer and the course of Irish politics, 1870-1917 | O'Callaghan, Edward | Thesis | | 1976 |
| Bishop Edward Thomas O'Dwyer and the fall of Parnell | O'Callaghan, Edward P. | Article in Journal | | 1978 |
| Correspondence between Bishop O'Dwyer and Bishop Foley on the Dublin Rising, 1916-17 | O'Callaghan, Edward P. | Article in Journal | | 1978 |
| English catholics and the Irish question, 1870-1893 | O'Callaghan, Edward Patrick | Thesis | | 1984 |
| Fr. Edward Thomas O'Dwyer and the general election of 1874 | O'Callaghan, Edward P. | Article in Journal | | 1979 |
| Letters and papers of Archbishop Ignazio Persico, Papal Commissary to Ireland 1887-8 : Part 3 | O'Callaghan, Edward P. | Article in Journal | | 1996 |
| Letters and papers of Archbishop Ignazio Persico, papal commissary to Ireland 1887-8. Pt. 2 | O'Callaghan, Edward P. | Article in Journal | | 1994 |
| Letters and papers of archbishop Ignazio Persico, papal commissary to Ireland, 1887-1888 | O'Callaghan, Edward P. | Article in Journal | | 1993 |