- Accounting--Handbooks, manuals, etc.1
- Actions and defenses1
- Administration1
- Administration of estates1
- Adrian VI, Pope, 1459-15231
- Advisory opinions (Islamic law)1
- Agazaria, Claudio Boncompagni di1
- Agriculture1
- Agustín, Antonio, 1517-1586. Dialogos de medallas inscriciones y otras antiguedades1
- Alba, Fernando Alvarez de Toledo, duque de, 1507-15821
- Albizzi, Costanza1
- Alchemy--Manuscripts1
- Alexander III, Pope, -11811
- Alfonso I King of Asturias, 693-7561
- Alfonso III, King of Asturias and Leon, approximately 848-approximately 9101
- Alfonso V, King of Aragon, 1396-14581
- Alfonso V, King of Asturias and León, 994-1027 or 10281
- Alfonso VI, King of Castile and Leon, 1030-11091
- Alfonso VII, The Emperor, King of Castile, 1104-11571
- Alfonso VIII, King of Castile, 1155-12141