| Agherton Parish, Portstewart : a brief history | Thomas, Avril | Monograph or Collective Volume | Display Aids | 1996 |
| Coleraine : Archibald Stewart's report and map, 1738 and 1758 | Thomas, Avril | Article in Journal | | 1998 |
| Derry - a spectacular maiden | Thomas, Avril | Article in Book | | 1995 |
| Derry ~ Londonderry | Thomas, Avril | Monograph or Collective Volume | Royal Irish Academy | 2005 |
| Drogheda, 1574 | Thomas, Avril | Article in Journal | | 1976 |
| Financing town walls in medieval Ireland | Thomas, Avril | Article in Book | | 1986 |
| Interconnections between the lands of Edward I : a Welsh-English mercenary force in Ireland, 1285-1304 | Thomas, Avril | Article in Journal | | 1993 |
| Londonderry and Coleraine : walled towns or epitome | Thomas, Avril | Article in Book | | 1999 |
| Londonderry c. 1856 : a city mapped in unusual detail | Thomas, Avril | Article in Book | | 2004 |
| The walled towns of Ireland | Thomas, Avril | Thesis | | 1989 |
| The walled towns of Ireland | Thomas, Avril | Thesis | | |
| The walled towns of Ireland. 2 vols. | Thomas, Avril | Monograph or Collective Volume | | 1992 |