Title
- On diphthongs1
- On generation and corruption3
- On mnemonics and memory1
- On the Anger of God1
- On the calibration of sundials1
- On the eternity of the world1
- On virtue1
- Opera6
- Operationes Ihesu Christi1
- Opus pacis1
- Opuscula6
- Opusculum de formandis epistolis1
- Opusculum de multiplici ludo1
- Oratio ad immortalitatem illustriassimae nec non famigerratissimae laudis1
- Oratio in laudem rei publicae venetorum1
- Orationes4
- Orationes in Laurentium Vallam1
- Orations3
- Orator ad Brutum1
- Order3