Title
- Observationes1
- Oculus sacerdotis1
- Odes1
- Office of the Dead1
- Office of the Mother of God1
- Ogasawara-den saiku kata kikigaki1
- Oleum effusum nomine tuum1
- Omnes ad praeda venient1
- Omnium gentium mores, leges, et ritus1
- On Questions in Aristotle’s Nicomachean Ethics1
- On accounting and commissions1
- On charms and talismans1
- On mnemonics and memory1
- On the Anger of God1
- On the calibration of sundials1
- On virtue1
- Ophthalmology text1
- Opusculum de formandis epistolis1
- Opusculum de multiplici ludo1
- Oratio ad immortalitatem illustriassimae nec non famigerratissimae laudis1