Encyclopedias, Almanacs, Transcripts, and Maps
- Appert, Nicolas François (1750-1841)
- Appius Claudius Caecus
- Applewhite, Jr., Marshall Herff (1931-1997)
- Applications of Number Theory in Cryptography
- Applied Ethics
- Applied Psi
- Apports
- Approximation
- Approximation
- APRO Bulletin
- Aquarian Age
- Aquarian Educational Group
- Aquarian Foundation
- Aquarian Tabernacle Church
- Aquarius Rising (Magazine)
- Aquino, Michael A. (1946-)
- Ar-Razi, also known as Abu Bahr Muhammad ibn Zakariyya
- Arab Contributions to Trigonometry
- Arachnoid Cysts
- Aradia