Author
- Polo, Marco, 1254-1323?1
- Pseudo-Bede1
- Pseudo-Cicero1
- Pseudo-Joachim of Fiore1
- Ptolemy1
- Rabanus Maurus1
- Ranieri Farnese1
- Ricardus, de Mediavilla, approximately 1249-1308?1
- Richard Bolter1
- Richard Rolle1
- Richard de Geveldale1
- Robert Ashley1
- Roberto Caracciolo1
- Rocca, Antonio1
- Seneca1
- Simon Bredon1
- Spain1
- Suetonius1
- Thomas Aquinas1
- Titus Livius1