- Astrolabes1
- Astrology2
- Astronomy1
- Astronomy, Arab1
- Audiore, Antonio1
- Augustine, of Hippo, Saint, 354-4301
- Aurispa, Giovanni, approximately 1376-14591
- Austria2
- Autographs1
- Autos-da-fé1
- Bardi, Giovanni de', conte di Vernio, 1534-16121
- Basil, Saint, Bishop of Caesarea, approximately 329-3791
- Bateman family1
- Batista de Lanuza y Tafalla, Miguel, -1659. Vida de la venerable Madre Geronima de San Estevan1
- Batista de Lanuza y Tafalla, Miguel, -1659. Vida de la venerable madre Feliciana de San Ioseph1
- Beards1
- Benefices, Ecclesiastical1
- Bettini, Giovanbattista1
- Bettini, Luigi1
- Bible. Old Testament2