- Aringhello, Tommaso di1
- Armaiolo, Puccino1
- Armaleoni, Benedetto degli1
- Armenia1
- Arrigo, Simone d'1
- Arrigucci family1
- Arrigucci, Caterina1
- Arrigucci, Luigi1
- Arte della lana (Guild : Florence, Italy)1
- Artedo, Petrus de1
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- Assumption of the Blessed Virgin Mary1
- Astrolabes1
- Astronomy--Tables1
- Attila, -4531
- Aurispa, Giovanni, approximately 1376-14591
- Averroës, 1126-1198. Talkhīs kitāb al-ʻIbārah1
- Averroës, 1126-1198. Talkhīṣ kitāb al-maqūlāt1
- Averroës, 1126-1198. Talkhīṣ madkhal Furfūriyūs1
- Baglioni, Niccolò1