Title
- Orationes3
- Orations6
- Order3
- Order of the Egyptian Fathers1
- Ordinal1
- Ordinances1
- Ordinary of the Mass2
- Ordinatio totius officii divini1
- Ordo benedicendi oleum catechumenorum et infirmorum et conficiendi chrisma1
- Ordo dedicationis ecclesiae et altaris1
- Ordo judicarius2
- Ordo missae1
- Ordo unctionis infirmorum eorumque pastoralis curae1
- Organon2
- Original leaves from famous Bibles, nine centuries 1121-1935 A.D. ...1
- Orthographia1
- Orthographical text6
- Ottoman Turkish expansion on qaṣīdat al-Burdah1
- Ouidius de remediis amoris1
- Oṃ gaṃ1