Title
- On charms and talismans1
- On mnemonics and memory1
- On the Anger of God1
- On the calibration of sundials1
- On virtue1
- Ontology text1
- Ophthalmology text1
- Opusculum de formandis epistolis1
- Opusculum de multiplici ludo1
- Orationes in Laurentium Vallam1
- Orations1
- Ordo judicarius1
- Organon1
- Otia imperialia1
- Ottoman Turkish expansion on qaṣīdat al-Burdah1
- Ouidius de remediis amoris1
- Pakṣatārahasya1
- Paludi pontine1
- Pand-i ʻAṭṭār1
- Panormia1