| AFM | J. O'Donovan, ed. and trans., Annala rioghachta Eireann / Annals of the kingdom of Ireland by the four masters, 7 vols. (1848–51); 2nd edn (1856); 3rd edn (1990) |
| AM Oxf. | Ashmolean Museum, Oxford |
| AM Oxf., Heberden coin room | Ashmolean Museum, Heberden coin room, Oxford |
| ANB | J. A. Garraty & M. C. Carnes, eds., American national biography, 24 vols. (1999) |
| APC | Acts of the privy council of England, new ser., 46 vols. (1890–1964) |
| APS | The acts of the parliaments of Scotland, 12 vols. in 13 (1814–75) |
| AS chart. | P. H. Sawyer, Anglo-Saxon charters : an annotated list and bibliography, Royal Historical Society Guides and Handbooks (1968) |
| ASC | D. Whitelock, D. C. Douglas, & S. I. Tucker, eds. and trans., The Anglo-Saxon Chronicle : a revised translation (1961) |
| Adams, Drama | W. D. Adams, A dictionary of the drama, 1: A–G (1904); 2: H–Z (1956) [vol. 2 microfilm only] |
| All Souls Oxf. | All Souls College, Oxford |
| Allibone, Dict. | S. A. Allibone, A critical dictionary of English literature and British and American authors, 3 vols. (1859–71); suppl. by J. F. Kirk, 2 vols. (1891) |
| Anderson, Scot. nat. | W. Anderson, The Scottish nation, or, The surnames, families, literature, honours, and biographical history of the people of Scotland, 3 vols. (1859–63) |
| Ann. Ulster | S. Mac Airt & G. Mac Niocaill, eds., Annals of Ulster (to ad 1131) (1983) |
| Ann. mon. | H. R. Luard, ed., Annales monastici, 5 vols., RS, 36 (1864–9) |
| Arber, Regs. Stationers | E. Arber, ed., A transcript of the registers of the Company of Stationers of London, 1554–1640 ad, 5 vols. (1875–94) |
| ArchR | Architectural Review |
| AusDB | D. Pike & others, eds., Australian dictionary of biography, 16 vols. (1966–2002) |
